Transcript Sports Nutrition

Sports Nutrition
Energy Balance
Kevin Browne
Learning outcomes
Energy Balance
• What does energy balance mean to you, in
your own words individually write down what
you understand by this term
• Pair (agree and write down your new
definition)
• Share
Energy Balance
• Energy balance is a term used to explain how
kilocalorie intake and kilocalorie expenditure are
related to each other, and in particular how they
can affect a person's body weight.
• If a person is at their ideal weight, then for that
person to maintain their weight, they would need
to ensure kilocalorie intake (through food and
drink) was equal to kilocalorie use (through
normal body functions and activity).
Energy balance equation
• The energy balance equation is:
• Energy Intake = Energy output
• If energy balance was a see-saw, it would be at
equal height on either side
More energy is
consumed (eaten)
than used
Energy in
Click buttons
to see effect
More energy is used
than consumed
(eaten)
Energy out
More energy is
consumed (eaten)
than used
Energy in
Click buttons
to see effect
More energy is used
than consumed
(eaten)
Energy out
More energy is
consumed (eaten)
than used
Energy consumed
(eaten) is same as
energy used
More energy is used
than consumed
(eaten)
Energy out
Energy in
Gains weight
More energy is
consumed (eaten)
than used
Energy consumed
(eaten) is same as
energy used
More energy is used
than consumed
(eaten)
Energy in
Energy out
Loses weight
Basal metabolic rate (BMR)
The Basic Metabolic Rate (BMR) is a calculation of how many kilocalories a person
needs for basic survival; this will have an impact on the energy balance and therefore
the ability for a person to lose, gain or maintain body weight. The BMR of an individual
is influenced by various factors such as:
•Climate
•Genetics
•Body shape and size
•Age
•Gender
•Metabolism
•Physical activity level
TASK
• Looking at all the factors that could effect
BMR
• I want you to come up with suggestions as to
how they could effect BMR
• Work in pairs
• 10mins
Climate
• Environmental conditions around a place
where a person lives, trains and competes will
have an effect on their Basal Metabolic Rate
(BMR).
• Where the climate is cold the body will need
to use more stored and consumed energy to
help stay warm. Where the climate is very hot,
the body will still need additional energy to
help maintain a safe, cool core temperature
Genetics
• Each person has a pre-programmed genetic
make-up which determines how they look,
feel, speak and perform. Part of the genetics
of a person will determine how they use
energy, and so this has a direct influence on
how many kilocalories are needed to function
• Some people are naturally more athletic than
others and so have a greater muscle mass. As
muscle uses energy to work, it is logical that a
person with a high muscle mass will need
more kilocalories in their diet to function
• A person who already has a large amount of
body fat will need to eat less consumed kcal
because of their fat stores.
Age
• As a person becomes older, their need for
kilocalories declines. This is particularly true
once a person reaches 25 years of age. At this
point, the body will have fully matured and so
will not need kilocalories for development
Gender
• Adult men usually have less body fat and more
muscle than women of the same age and size.
Muscle burns more calories than fat does, so
men's need for energy is usually 5-10% higher
than women's
Metabolism
Every person has a minimum requirement of kilocalories in order to survive and
function as a human known as the Basal Metabolic Rate or BMR (this is what most
people mean when they talk about their 'metabolism').
A person's BMR is expressed in kilocalories and gives an indication of how many Kcals
need to be consumed in a day to survive, however, this is for someone that is
sedentary.
An easy way to calculate the BMR of a sedentary person is to use the formula:
BMR = Weight (kg) x 25 Kcal
To use the BMR calculation for an active person, it is necessary to adjust the kilocalorie
requirements because the person will naturally need more kilocalories to function.
The adjustment can be made using a system of levels known as the physical activity
level.
Physical activity
• A very active person will naturally need to consume more
kilocalories to ensure that they maintain the energy
balance, while a person who very rarely exercises will need
very few additional kilocalories in order to maintain energy
balance.
• To help calculate the total daily kilocalories a person needs,
the Physical Activity Level (PAL) identifies how many
additional kilocalories a person will have to consume to
meet the demands of their lifestyle. T
• he additional kilocalories are identified as a percentage
that is added on to the basal metabolic rate, giving an idea
of the amount of kilocalories needed for that person every
day.
Cont…
• The actual amount of kilocalories expended
during sport/exercise depends on lots of different
factors including:
• Frequency - how often a person trains/competes
• Intensity - how hard a person trains/competes
• Time / duration - how long a person
trains/competes for
• Type of sport/exercise - different activities use
different amounts of energy
Physical Activity Level (PAL)
Description
Percentage multiplier
Sedentary
Someone who probably works in an
office and rarely exercises apart from
occasional walks around shops at the
weekend. This type of person would
not consider exercise and activity
important.
20%
Moderately active
Someone who is probably either
active all day as part of their job or
who may cycle/walk to work. They
may be a member of a gym or they
may play sport on a recreational
basis, up to 4 times per week. They
could also keep fit as part of a
competitive training programme for a
predominately skill based sport.
50%
Very active
Someone who either has a very
active job such as a builder, or
someone who plays sport at a
competitive level and trains every day
for at least two hours at a high
intensity.
100
Calculating BMR
• So, to calculate a person's daily kilocalorie
requirement who is moderately active and
weight 70kg:
• BMR ( weight (Kg) x 25Kcal
• BMR ( 70 x 25 = 1750Kcal
• Daily Kilocalorie requirement ( 1750Kcal + 50%
(PAL) = 2625Kcal
The Basal Metabolic Rate
What is Basal metabolic rate?
BMR: The rate at which the body uses
energy for maintenance activities
How is this calculated?
Men = 1 calorie / kg of bodyweight / hr
Women = 0.9 calorie / kg of bodyweight / hr
E.g: A man weighing 84kg would calculate his
BMR as:
1 x 84kg x 24 hrs = 2016 basal caloric needs.
N.B. This calculation is just an estimate.
How can we make the calculation
more accurate?
The Harris Benedict equation for BMR:
For men:
BMR = 66 + (13.7 x wt [kg]) + (5 x ht [cm]) – (4.7 x age [yrs])
For Women:
BMR = 655 + (9.6 x wt [kg]) + (1.8 x ht [cm]) – (4.7 x age [yrs])
E.g. A man weighing 84kg, 180cm in height, & 40 years old would calculate:
BMR
= 66 + (13.7 x 84 [kg]) + (5 x 180 [cm]) – (4.7 x 40 [yrs])
= 66 + 1150.8 + 900 – 272
= 1844.8 calories
Task
Calculate your BMR using this formula
SBN May 2009 AS Physical Education
Questions
1. Calculate the BMR of an adult male weighing
90kg
2. Calculate the BMR of an adult female
weighing 65kg
3. Calculate the BMR of an adult male who
weighs 84kg, is 32 years old and 184cm tall
4. Calculate the BMR of an adult female who
weighs 57kg, is 27 years old and 165cm
SBN May 2009 AS Physical Education
Learning outcomes Review
• To know and understand what Basal metabolic
rate is
• Identify factors that can effect BMR
• Explain how these factors affect BMR
• Calculate BMR using a simple equation