Slide 1

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 2

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 3

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 4

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 5

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 6

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 7

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 8

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 9

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 10

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 11

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 12

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 13

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 14

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 15

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 16

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 17

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 18

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 19

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 20

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 21

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 22

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 23

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 24

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 25

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 26

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 27

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 28

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 29

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 30

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 31

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 32

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 33

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 34

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 35

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 36

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 37

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 38

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 39

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 40

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 41

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 42

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 43

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 44

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 45

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 46

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 47

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 48

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 49

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 50

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 51

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 52

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 53

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 54

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 55

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 56

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57


Slide 57

THE PHYSIOLOGY OF
EXERCISE
1125
Steven C Seideman
Extension Food Processing Specialist
Cooperative Extension Service
University of Arkansas
1

INTRODUCTION
The lack of exercise was never been a
problem until the middle of the 20th century
when the industrial age, with its
automation, replaced much of the physical
work in the United States.
This module briefly discusses the history,
benefits, types and purposes of physical
activity.
2

RECENT POPULARITY
Prior to the 1980s, physical education was
required in most schools for purposes of
preparing the youth for jobs that required
physical strength.
The majority of the physically demanding jobs
decreased and the general population believed
that physical exercise was not the best way to
spend their leisure time.

3

RECENT POPULARITY
Physical activity was replaced by computer
games, television and other non-physical
activities.
Along with this shift toward less physical activity,
came the problems with feelings of stress,
obesity, diabetes, heart disease, and rampant
depression among other physical problems.
The obvious solution is EXERCISE.

4

RECENT POPULARITY
People who exercise today can be divided
into several groups;
1)People interested in weight loss
2) People that believe that exercise will
increase their longevity.
3) People who believe ”If some exercise is
good, more is better” and ultimately
become addicted to exercise.

5

People Interested in Weight
Loss
If being overweight is caused by excessive
caloric intake (a fact) there are two things we
can do to remedy it; 1) Reduce our intake (diet)
and 2)Burn excess calories via exercise.
More information on nutrition can be found
elsewhere in this series (Introduction to Human
Nutrition; Module 1219).
As a guide, 30 minutes of vigorous exercise 3 to
4 times per week is considered a good program
to maintain one’s weight.

6

People That Believe Exercise will
Increase Their Longevity
There is very little scientific data to support the belief that
exercise will increase longevity, however the quality of
life will generally improve.
For example, if you do not exercise, you may develop
diabetes. In today’s world of modern medicine, you may
live with diabetes the same number of years as if you
didn’t have it, however, you may have your legs
amputated, go blind or suffer other circulatory diseases.
Longevity tends to be more genetically determined and
not altered as much as most believe by lifestyle and
exercise.

7

“If Some exercise is good, more
is better” Addicted
These are the exercise fanatics.
They live to exercise as opposed to
exercise to live.
These are the people who run several
miles a day and occasionally run 26 mile
marathons.
They get literally “addicted” to exercise.

8

THE BENEFITS OF
EXERCISE

9

10

The Benefits of Exercise
The benefits of exercise can be divided
into several categories;
1) Health Benefits
2) Mental Benefits
3) Physical Benefits

11

HEALTH BENEFITS
1) Heart Disease and Stroke - Daily physical
activity can help prevent heart disease and
stroke by strengthening your heart muscle,
lowering your blood pressure, raising your
HDL (good cholesterol) and lowering your
LDL (bad cholesterol), improving blood
flow, and increasing you heart’s capacity
to work.

12

Health Benefits
2) High Blood Pressure – Regular exercise
reduces blood pressure in people with high
blood pressure (hypertension).
3) Diabetes – By reducing body fat, physical
activity can help to prevent and control type 2
diabetes.
4) Osteoporosis – Regular weight-bearing exercise
promotes bone formation and may prevent many
forms of bone loss associated with aging.

13

Mental Benefits
1) Exercise will reduce depression and anxiety and help
you to better manage stress.
2) Promotes better, more restful sleep.
3) Long term, vigorous exercise causes the brain to release
“dopamines” which create a feeling of well-being. This
is often referred to as a “runners high”. It is your body’s
natural “high”.
4) Succeeding at setting a physical activity goal and
attaining that goal contributes to a feeling of
accomplishment.
5) Self esteem is often raised by reducing ones weight.

14

Physical Benefits
Physical exercise reduces some of the effects of
aging.
Keeps joints, tendons and ligaments flexible so
it’s easier to move around.
By increasing muscle strength and endurance
and improving flexibility and posture, regular
exercise can prevent back pain.
By losing weight via exercise, loss weight is
suspended in hip, knee and ankle joints thereby
increasing their usefulness.

15

TYPES OF EXERCISE

16

Types of Physical Activity
For weight control and general physical activity,
many types of daily activities can help;
SPORTS
PLANNED EXERCISE PROGRAMS
HOUSEHOLD CHORES
LAWN WORK
All the above have some beneficial effect.

17

Types of Planned Exercises
Exercises are broadly classified as one of
two types;
1) Aerobic
2) Anaerobic

18

Aerobic Exercise
Aerobic exercises are those that require a
substantial amount of oxygen over an extended
period of time and causes you to breathe more
deeply and your heart to work harder to pump
blood. It is also known as “cardiovascular
exercise”. It improves the health of your heart,
lungs and overall cardiovascular system.
Examples include walking, jogging, running,
aerobic dance, bicycling, rowing, swimming and
cross-country skiing.

19

Anaerobic Exercise
Anaerobic exercise usually refers to
resistance training whereby large amounts
of oxygen are not needed.
Anaerobic exercise is done primarily for
increased muscle mass and bone
strength.
Examples include weight lifting, sit-ups,
push-ups, stretching, etc.

20

Rate Limiting Steps
In aerobic exercises where large groups of
muscles are used repeatably over a long period
of time, the rate limiting step is the update and
utilization of oxygen.
In anaerobic exercise, where only single or small
localized muscle groups are utilized, the rate
limiting step is in the number of sarcomeres
present in the muscles used.

21

The Amount/Type of Exercise
Recommended
Most experts suggest 30 minutes/day of
moderate-intense aerobic exercise 3 or
more times per week plus some form of
anaerobic exercise twice per week.

22

HOW TO GET STARTED
The single most important ingredient is
determination.
Decide on the best time of day (morning, noon
or evening).
Decide on the type of activity (walking, jogging,
stretching etc).
Set an exercise plan starting slow and easy and
building up more as time passes.
You don’t need fancy equipment- good shoes
and appropriate clothing are enough.

23

SAMPLE PLAN
Here is a get-started simple plan.
1) Get up 1 hour earlier than usual.
2) Do about 10 minutes of serious stretching
exercises.
3) Walk vigorously for 30 minutes.
4) Do 10 to 20 sit-ups and push-ups.
5) Shower
6) Go to work. Notice the improvement in attitude
and reduced anxiety.

24

The Physiology of Exercise

25

The Physiology of Exercise
This section will take you through the
concept of calories in foods, the body
tissues and the biochemistry of exercise .

26

FOOD
Food consists of water, carbohydrates, fats/oils,
proteins, vitamins and minerals.
Water is by far the most abundant but contains
no calories.
Vitamins and minerals are present in very small
amounts and do not contribute to calories.
This leaves us with carbohydrates, fats/oils and
proteins.

27

CALORIES
Calories associated with food
components;
Carbohydrates – 4.5 kcal/gram
Proteins- 4.5 kcal / gram
Fat- 9 kcal/ gram

28

Food Components
Carbohydrates, fats and proteins are all
inter-convertible in the body.
This is a very important yet poorly
understood concept.
If we eat a 3,000 calorie per day diet and
only utilize 2,000 calories, the remaining
1,000 will be stored in the body in a priority
order, usually as fat.
This could conceivably mean that if you ate
3,000 calories of only carbohydrates and
protein, it would still be stored as fat if not
utilized.
29

The Burning of Food
The Krebs cycle or tricarboxyclic acid
cycle utilizes carbohydrates, fats and
proteins to generate energy (ATP), CO2
and water (sweat).

30

PRIORITY OF NUTRIENT
UTILIZATION
Our body has a priority in which nutrients
(carbohydrates, fats and proteins) are utilized by
various tissues.
1) Nervous System
2) Skeletal system-bones
3) Muscle
4) Fat

31

Priority of Nutrient Utilization
If we exercise, our nutrient supply is used
at the muscle level and fat is never
formed.
This same priority system reverses when
we experience lack of nutrients. We start
using fat for energy and then begin to burn
muscle as fat stores are depleted.

32

THE MARATHON RUNNER

33

34

THE MARATHON RUNNER
Can you imagine what happens as a person
runs a 26.25 mile marathon?
1) The first utilized component is glucose in the
blood. Blood sugar, or glucose, generally only
lasts 15- 20 minutes. When we run low of blood
glucose, our brain generally signals us that we
are hungry. Immediately before a big race, you
often see athletes eating chocolates bars for that
instant energy.

35

36

THE MARATHON RUNNER
2) As blood glucose starts to bottom out, the
runner begins to utilize muscle glycogen.
Muscle glycogen are long chain glucose
molecules stored in the muscle that look
like sand under an electron microscope (
see next slide). This glycogen supply can
last 30 minutes to an hour.

37

38

The Marathon Runner
3) As the glycogen level becomes lower, the
runner starts utilizing fat as energy. We all
have stores of fat in various parts of our
body. Distance runners generally have
very little subcutaneous ( under the skin)
fat. Fat is also stored around kidneys, in
between muscle groups and even within
the muscle.

39

THE MARATHON RUNNER
4) As the marathon runner begins to run out
of easily utilizable fat, they begin to utilize
muscle for energy. If not much muscle is
used for energy by the runner, they will
recover from the run fairly quickly,
however, if excessive muscle utilization
has taken place, recovery could last over a
month.
40

DIETING
The same chain of events (utilization of glucose,
glycogen, fat and then muscle) are exactly the
same if one goes on a diet.
Anorexia Nervosa, a condition where a person is
mentally repulsed by food, goes through the
above process and if not treated, the person
dies from digesting their heart ( a protein).

41

BODY TISSUES

42

FAT CELLS
Fat is the ultimate storage depot for unutilized energy.
Fat cells, call adipocytes are actually cells that develop
and become filled with fatty acids.
If one exercise, the fatty acids are utilized for energy and
one experiences a loss of weight. However, as one “falls
off” the diet, the adipocytes refills with fatty acids quite
easily. Therefore, to be successful, one must stay on the
diet and keep the fatty acids out of the adipocytes for 6
months to a year in order for the adipocyte to disappear.

43

44

45

MUSCLE AND MUSCLE
FIBERS

46

MUSCLE FORMATION
Before we were born, our muscle cells formed
into fibers whereby at birth our number of
muscle fibers were determined and cannot be
changed.
We can increase the length and diameter of
muscle fibers through exercise.
Weight lifters subject muscle to increasing loads
and repetition whereby the muscle is damaged.
After a day or two, they again subject muscle to
damage.
47

Muscle Formation
The body responds to this damage by not
only repairing itself but repairing itself to
resist even damage. Correspondingly, the
muscle get larger by adding more,
structural components called sarcomeres
and by adding more mitochondria.

48

49

Muscle Fiber Types
All muscle contain muscle fibers that are
one of three types.
RED, WHITE and INTERMEDIATE
Notice the difference between beef
(primarily red muscle fibers) vs chicken
breast ( primarily white muscle fibers)

50

Characteristics of Muscle Fiber
Types
RED
-More myoglobin
-More fat
-More mitochondria
-Small in diameter
-Aerobic metabolism
-Dark in color
-High in iron
-Less glycogen
-Slow twitch but very strong

WHITE
Less myoglobin
-Less fat
-Less mitochondria
-Large diameter
-Anaerobic metabolism
-Light in color
-Less iron
-More glycogen
-Fast twitch but weak

51

52

53

Muscle Fiber Types
Intermediate muscle fibers are in between red
and white in characteristics.
All muscles vary by location, type of exercise,
function, etc,
Some experts claim you can exercise to obtain a
certain fiber type ( sprinter vs distance runner)
Some experts claim the muscle fibers are
genetically determined (take biopsy to determine
your ability to either sprint or run distances).

54

MUSCLE FIBER EXAMPLES
Duck breast muscle vs chicken breast
muscle.
Hummingbird vs crow
Beef vs pork vs chicken
Support muscles vs muscles used for
locomotion.

55

SUMMARY
Physical exercise has many benefits and should
certainly become a part of our lifestyle.
Understanding how the human body responds to
food and exercise at the tissue and cellular level
is important to developing a well-rounded
exercise program including both aerobic and
anaerobic types.

56

57