Transcript Document 7201443

Presented By:
Jessica Calhoun
Heather Mason
Thusita Kannangara
October 11, 2010
Image fromtalk.gagajoyjoy.com
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Americans have become obsessed with protein!
In gyms, restaurants, medical offices and stores
we are bombarded with ads and displays of
protein supplements.
Many of these beliefs about protein are
incredibly exaggerated or just plain wrong.
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Derived from Greek “of first rank” or
“primary”
Found in 40% of skeletal muscle, 25% in organs
and the remainder in the skin and blood
Play vital roles in almost every biological
process
Macromolecules composed of C, H, O and N
which are formed when large amounts of
subunits or amino acids link together creating
long chains
Composed of amino acids
(AA’s)
 Contain a central carbon
atom, amino group (NH2),
carboxylic group (COOH), and a side chain.
 Twenty AA’s, 9 essential
 Complete proteins contain
all 9 essential AA’s
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Image brainandbeauty.com
ALL ANIMAL SOURCES
VEGETABLE SOURCES
 Meat
 Soy
 Poultry
 Tempeh
 Fish
 Grains
 Milk
 Nuts
 Cheese
 Beans
 Yogurt
 Soy/ Almond milk
 Starchy vegetables
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Requirements reflect the need to offset protein
losses to maintain nitrogen homeostasis
Proteins constantly being synthesized and
degraded “protein turnover”
Most AA’s are recycled, but a small portion are
oxidized and must be replaced
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Protease enzymes in the stomach and small intestine
(SI), break down the amino acid chains in proteins into
polypeptides
 then further separate into individual amino acids.
Absorption occurs along the SI
Absorption of AA’s into the intestinal cells requires
carriers; but paracellular absorption can also occur
 In general, BCAA absorbed faster than smaller amino
acids
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DRI for healthy individuals: 0.8 g/kg/day
Strength and endurance athletes may have
increased needs
Endurance athletes: 1.2 to1.4g/kg/day
 9-10% daily energy
Resistance athletes: 1.6 to 1.7g/kg/day
 14-15% daily energy
Extra protein is needed to repair damaged muscle
fibers, decrease the rate of muscle protein
breakdown, replenishment of depleted energy
stores, and synthesis of new protein molecules
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18th century: muscles primarily composed of
protein
18th century: Belief that protein was the major
fuel source during exercise
Observations of affluent laborers diets lead to
the “Voit Standard” or 118 grams of pro/day
1904: 35–50 g of protein a day was believed
adequate for adults
2010: It is understood that the major energy fuel
source is carbohydrates and not protein
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Coronary artery disease
Dehydration
Increased Calcium excretion
Supplements – possible risk for toxicity and
metabolic imbalances
Strain on liver and kidneys
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Edema
Anemia
Muscle atrophy
Hormone imbalance
Severe cases: Marasamus & Kwashikor
http://www.bio.ilstu.edu/armstrong/syllabi/cassava/cassava8.htm
Branched-Chain Amino Acid Supplementation
and Indicators of Muscle Damage After
Endurance Exercise
Greer, B. , Woodard, J. , White, J. , Arguello, E. , & Haymes, E. (2007). Branched-chain
amino acid supplementation and indicators of muscle damage after endurance exercise.
International Journal of Sport Nutrition & Exercise Metabolism, 17(6), 595-607.
Image- the-fitness-motivator.com
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Determine if branched-chain amino acid (BCAA)
supplementation decreases indicators of muscle
damage compared with a carbohydrate (CHO)
beverage or a noncaloric placebo (PLAC) beverage.
Image Justsupplements.com
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Goal is to reduce muscle damage during training
BCAA may reduce the extent of muscle damage
via the release of anabolic hormones or by
inhibiting proteolysis
Ingesting BCAA’s pre and post workout has
been shown to decrease post exercise creatine
kinase (CK) and lactate dehydrogenase (LDH)
activities
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Nine untrained, healthy college men
Kept detailed diet record and were encouraged to
maintain the same dietary pattern
Avoid eating for 3 hours before each trial
Subjects assigned to 1 of 3 treatment orders
Exercise at 50% V02 max for 90 min.
Beverages were administered at 5 minute pre exercise
and at 60 min. mark.
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Subjects blinded to beverage, same taste and
appearance
1. BCAA beverage – isoleucine, leucine, valine (200
kcal)
2. Isocaloric CHO beverage (Gatorade) (200 kcal)
3. PLAC- noncaloric, water, artificial sweetener,
lemon flavor, and salts
Image agron.iastate.edu
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Creatine kinase (CK)
Lactate dehydrogenase (LDH)
Isokinetic leg extension torque
Led flexion torque
Muscle soreness of quads (self rating)
Measurements taken before exercise and at 4,
24, and 48 hours post exercise
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CK activities significantly lower after the BCAA
trial than in the PLAC trial at all times, only
lower than the CHO at 24 h
CK lower in the CHO trial than PLAC at 24
and 48 h
LDH was lower in the BCAA trial at 4 H, no
sig. difference between CHO and BCAA
No sig. effects for leg extension torque
Leg flexion torque in the BCAA trial was
significantly greater than both the CHO and
PLAC trials at 48 h postexercise
Leg Extension torque increased,
but not significantly
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Leg Flexion Increased
significantly at 48 h
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Data suggests BCAA supplementation attenuates muscle
damage during prolonged endurance exercise in untrained
college age men
Smaller changes in markers in this study than previous,
isocaloric?
Intensity too low?
AA with coingestion of CHO may be more effective than AA
alone
Possible mechanism- when ingested before aerobic exercise
BCAA increases concentrations of human growth hormone and
helps attenuate a drop in testosterone, resulting in more anabolic
environment
Strengths
Subjects blinded
Isocaloric beverage
Average athlete, not
highly trained
 All subjects performed
all three trials
 Separated by 8 weeks
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Limitations
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Researchers not blinded
No women
Small sample size
Intensity too low?
Only theorized
mechanism
Timing Protein Intake Increases Energy
Expenditure 24 h after Resistance Training
Hackney, K., Bruenger, A., Lemmer, J. (2010). Timing Protein Intake Increases Energy
Expenditure 24 h after Resistance Training. Medicine and Science in Sports and Exercise.
42(5), 998-1003.
http://tiptoptone.com/resistance_training.html
To determine the effect of protein (PRO)
supplementation before an acute bout of heavy
resistance training (HRT) on post exercise resting
energy expenditure (REE) and the non protein
respiratory exchange ration (RER).
Hypothesis: REE would be increased and RER would be
decreased up to 48 hours after HRT in those receiving
PRO compared with CHO
Double-blind two trial crossover design
6 resistance trained men, 3 trained women
Measure one rep max (RM)
4 day dietary journal
Consumed supplement 20 mins before single bout of
HRT
 PRO supplement- 18 g whey, 2 g CHO, 1.5 g fat
 CHO supplement- 19 g CHO, 1 g PRO, 1 g fat
 REE measured 4 consecutive days with Sensor Medics
metabolic system
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REE elevated significantly in both CHO and
PRO groups at 24 and 48 h post HRT
REE in response to PRO was significantly
greater compared with CHO at 24 h
RER decreased significantly in both groups at
24 h compared to baseline
No differences observed in total energy intake
or HRT volume = sets x reps x kg lifted
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Reduced RER indicates there is greater
reliance at fat oxidation at rest
Ingesting protein before HRT may be an
effective way to increase energy expenditure
Increases in REE may lead to improvements
in body composition
Volume was not increased so did not increase
strength!
Strengths
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Men and women
Double-blind
Controlled diet
40 references, many
within the last 10 years
Limitations
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No control group
Small sample size
Could use more graphs
for clearer data
presentation
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Health, ethical, religious reasons
Range of vegetarianism from semi veg. to vegan
Observational studies have not detected
differences in performance
Short term intervention studies have had similar
results
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Protein about 85% digestible from plant diet compared
to 95% with mixed diet
RDA .9 g protein/ kg BW/ day for regular human
Most people surpass this amount
RDA could be increased to 1.3 to 1.8 g/ kg for athlete
No need for strict combination of foods
Choose a variety of plant sources from all food groups
and achieve adequate protein balance
Vegan
 Soy Milk
 Tofu
 Tempeh
 Certain Veggie burgers
 Nuts
 Peanutbutter
 Beans
 Corn, potatoes
 Whole grains
Image al.godsdirectcontact.org
Vegetarian
 Vegan foods plus
 Milk
 Eggs
 Cheese
 Fish?
Effect of dietary protein content during
recovery from high-intensity cycling on
subsequent performance and markers of
stress, inflammation, and muscle damage in
well-trained men
Rowlands, D. S., Rossler, K., Thorp, R. M., Graham, D.F., Timmons, B. W.,
Stannard, S.R., Tarnopolsky, M. A. (2008). Effect of dietary protein content
during recovery from high-intensity cycling on subsequent performance and
markers of stress, inflammation, and muscle damage in well-trained men.
Applied physiology, nutrition, and metabolism, 33(1), 39-51.
http://www.treehugger.com/files/2008/09/helmet-debate-is-over.php
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It may be most beneficial to consume protein
during immediate hours of post exercise.
Exercised muscle has increased blood flow,
amino acid uptake and protein synthesis
Amino acid uptake from high protein meal
appears to be greatest following exercise
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Evaluate the effect of post exercise protein
consumption on next day high intensity cycling
performance
Investigate presence of recovery and evaluate
high intensity performance after 3 days.
Double-blind, randomized, crossover design
12 trained male cyclists
Cyclists performed 3, 2.5 hour programmed cycling
endurance exercise tests over a 4 day period in the
laboratory. Day 3 was a rest day.
 Day 1 & 2, each cyclist consumed treatment.
 The protein group received 0.8 g of pro/kg/hr in
form of bar or beverage. Control group consumed
0.12 g pro/kg/hr and 2.35g cho/kg/hr
 Instructed to consume 8 times throughout a 4
hour period.
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Day 1 – Cycling protocol performed. Treatment
was given and blood samples taken every 30
min over 3 hour period.
Day 2 – Blood samples -> cycling protocol ->
treatment -> blood samples 3x in 90 minutes.
Day 3 – Rest day. Rich CHO diet provided to
replenish glycogen stores
Day 4 – Repeat performance of day 2
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Sensation perception charts for sprints and
intervals on days 2 and 4
Plasma lactate, glucose, creatine kinase (CK)
cortisol, interleukin-6, C Reactive Protein
(CRP), tumor necrosis factor,
Net nitrogen balance
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Overall mean sprint power in protein group was
greater on day 4 and less in control group
Minor increases in strength and less nausea
reported in protein group on day 4
Relative to control, protein group had reduced CK
before exercise on day 4
Day 1 post exercise to day 2, control had positive N
balance and negative in control.
Relative to control, plasma lactate was higher in
control during sprints
No significant differences in glucose, cortisol &
Interleukin 6
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High protein post exercise diet followed by a
high carbohydrate diet may enhance endurance
sprinting performance in subsequent
performance days.
http://gymaddicts.com/the-benefits-of-protein-bars/
STRENGTHS
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Ample background
information
Cycling protocol was
programmed into cycle
software
Semi- realistic environment
Thorough explanation of
measurements
Invites more research on
recovery and performance in
endurance athletes
LIMITATIONS
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Small sample size (n=12)
Low external validity 30 y/o male
cyclists
Cyclists complained of being full
Unrealistic to consume frequent
and large amounts of pro
bars/beverages post exercise
Invasive
Possible Day 2 and Day 3 non
dietary compliance
Limited similar studies
Minimal studies with endurance
athletes and protein recovery
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Hoffman, J. R., Ratamess, N. A., Tranchina, C. P., Rashti, S. L., Kang, J.,
Faigenbaum, A. D. (2009). Effect of a proprietary protein supplement on
recovery indices following resistance exercise in strength/power athletes.
Amino acids, 38(3), 771-778.
http://www.eshop-healthcare.com/muscle-milk-high-protein-shake-mix/
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To evaluate the effect of pre and post exercise
protein ingestion on recovery in resistance
exercise
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Double-blind, randomized design. Participants
were matched for strength
15 male strength/football athletes
Supplement group consumed 42 grams of
proprietary protein blend (“New Whey Liquid
Protein”) pre and post exercise.
Placebo group consumed protein free beverage
Reported to a performance laboratory four
different sessions (T1-T4)
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T1 - Athletes tested for maximum strength
T2 - Treatment consumed 10 minutes prior to
exercise and 15 minutes post exercise. Blood
samples taken pre and post exercise
Lower body resistance exercise was performed
at 80% maximum strength
T3 & T4 - muscle soreness rating, treatment,
resistance exercise, treatment, blood samples pre
and post exercise
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Soreness questionnaire
Blood samples to measure serum testosterone,
cortisol, hemoglobin and hematocrit
Dietary recall
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Dietary recall - no difference in energy
expenditure between the groups
No significant difference in muscle soreness
PL performed significantly fewer repetitions at
T3 and T4 than they did at T2
SUP performed better than the placebo group
at T3 and T4 when compared T2
PL elevated CK in T3 and T4. SUP CK
remained stable
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Protein ingestion pre and post resistance
exercise may have a greater improvement in
exercise recovery in the following days
STRENGTHS
Ample background
information
 Variety of references
 Unexpected findings were
explained with other studies
 States that more research is
needed in regards to protein
timing and muscle repair
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LIMITATIONS
Limited sample size (n=15)
Low external validity – study
only looked at college male
resistance/football athletes
 Results not attributed to pre or
post PRO ingestion individually
 One of the first studies to
show significant recovery from
PRO SUP pre and post exercise
 Dietary recall was taken 1 week
prior to study
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Milou, B., Koopman, R., Gijsen. A., Vandereyt, H., Kies, A. K., Kuipers,
H., Saris, W.H.M., VanLoon, L.J.C. (2008). Protein co-ingestion
stimulates muscle protein synthesis during resistance type exercise.
American Journal Physiological Endocrinal Metabolism, 5:70-77.
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Few studies have examined the effect of coingestion protein and carbohydrate on muscle
protein synthesis during exercise.
The results of these studies show that the
stimulation effects of CHO + Protein on body
protein synthesis during endurance and
resistance type exercise
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Assess the effect of protein and carbohydrate
supplementation on synthesis of muscle protein
and whole body protein balance during
resistance exercise at fed state.
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Ten healthy male volunteers
All subjects participated in two screening
sessions
Body composition –using hydrostatic weighing
Leg volume
Maximal oxygen uptake capacity
One repetition maximum – for two legs
Work load capacity
All subjects received a standardized diet of 54.3
±1.8 kJ/kg body weight, consisting of 62%
Carbohydrate, 22% Fat, and 16% Protein evening
before each experimental day.
• During experimental day 0.16±0.01MJ.kg body wt 1.day-1, consisting of 62% carbohydrate, 13%
Protein, and 26% Fat.
• Subjects ingested 78±g protein via standardized
diet and additional 21±1 g from CHO+ Protein
treatment
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Each subject participated in two treatments
separated by two weeks
• During 2hr resistance type exercise either
carbohydrate or Carbohydrate +protein treatment
received
• Subjects received a dose of 0.15g.kg-1.h-1
carbohydrate (50% glucose and50%maltodextrin),
with or without 0.15g.kg-1.h-1 protein hydrolysate
beverage (1.5ml/kg)every 15 mins during exercise
• Arterialized blood samples and muscle biopsies
were taken every 15 min( t=0 and t=120)
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Whole body net protein balance positive in
CHO +Protein treatment
CHO treatment achieved negative net protein
balance
Whole body protein breakdown rates lower in
CHO+ Protein experiment
Mixed muscle protein synthesis rates higher in
the CHO+ PRO treatment
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Protein co-ingestion with carbohydrate
improves whole body protein balance and
increases mixed muscle protein synthesis rate
during resistance type exercise
STRENGTHS
LIMITATIONS
Same group of
participants used in both
experiments (act as own
control)
 Athletes performed in a
fed state
 Recent reference articles
(after 2000)
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Small sample size (n=10)
They were not elite or
trained athletes
 Do not participate in
any regular sports
activities.
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When counseling athletes in regards to protein
needs and exercise, it is important to understand
the athletes needs and goals to help them
perform optimally.
A tool that dietitians can be use when
counseling athletes in regards to protein needs
and exercise.
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Connected through 4 Levels
Macrosystem: wider society, culture, media and
Ex. Athletes are susceptible to media and
advertisements of high protein diets,
supplement use and are often intrigued by such
items that claim to performance.
Mesosystem: school policies, trainers and coaches
Ecosystem: family values, norms and expectations
Macrosystem: personal beliefs, values and skills
http://gozips.uakron.edu/~susan8/devparch/urie.jpg
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In regards to protein and exercise, dietitians are
often called on to design athletic diets
Understand the sport, physical requirements,
time dedication, living situation, cultural needs,
age, goals and education level
Recommendations can be made based of the
athlete’s everyday influences
Increased communication and understanding
between the athlete and dietitian
Lead to improved athletic performance
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"Mix one part fact with several
parts ignorance; season with
advertising, sprinkle on a need for
that all-important competitive edge,
and you have a recipe for protein
supplements" (Caffery, 2010)
http://rawfoodsos.com/2010/02/16/the-greatprotein-debate-part-2/
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Protein ingestion before exercise has been shown
effective in decreasing muscle soreness and improving
repetition performance in resistance trained athletes
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Protein has shown to improve mean sprint
performance in well trained endurance cyclists
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Supplementation is overused in college athletes and has
not proved to be more effective than dietary protein
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Further research is needed to determine the optimal
amount and timing of protein needed for sports
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carbohydrate- protein supplement. Medicine and science in sports and exercise, 38:6, 1106-1113.
Berning, J. R., & Steen, S. N. (1998). Nutrition for sport & exercise (2nd Ed.). Gaithersburg, MD: Aspen Publishers, Inc.
Biolo, G., Tipton, K.D., Klein, S., Wolfe, R.R. (1997). An abundant supply of amino acids
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Biolo, G., Maggi, S. P., Williams, B. D., Tipton, K. D., Wolfe, R.R. (1995) Increased rates of muscle protein turnover and
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Butterfield, G.E. (1987). Whole body protein utilization in humans. Medicine and science in sports and exercise, 19:157-165.
Chelsy, A., MacDougall J. D., Tarnapolsky, M. A., Atkinson, S. A., Smith, K. (1992). Changes in human muscle protein
synthesis after resistance exercise. Journal of Applied Physiology, 73:1383-1388.
Feldman, R. S. (2008). Development across the life span (5th ed.). New Jersey: Pearson Prentice Hall
Gropper, S.S., Smith, J.L., Groff, J.L. (2009). Advanced nutrition and human metabolism (5th Ed.). Belmont, CA: Wadsworth
Publishing.
Greer, B., Woodard, J., White, J., Arguello, E., & Haymes, E. (2007). Branched-chain amino acid supplementation and
indicators of muscle damage after endurance exercise. International Journal of Sport Nutrition & Exercise Metabolism, 17(6),
595-607.
Hackney, K., Bruenger, A., Lemmer, J. (2010). Timing Protein Intake Increases Energy Expenditure 24 h after Resistance
Training. Medicine and Science in Sports and Exercise. 42(5), 998-1003.
Ivy, J. I., Ding, Z., Cialdella-Kam, L. C., Morrison, P. J. (2008). Post exercise carbohydrate – protein supplementation:
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Ivy, J. L., Goforth J. H., Damon, B. M., MacCauly, T. R., Parson, E.C., Price, T. B. (2002). Early post exercise muscle glycogen
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MacDougall, J. D., Gibala, M. J., Tarnapolsky, M. A., Macdonald, J. R., Interisano, S.A.,
Yarasheski, K. E. (1995). The time course for elevated muscle protein synthesis following heavy resistance exercise.
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Milou, B., Koopman, R., Gijsen. A., Vandereyt, H., Kies, A. K., Kuipers, H., Saris, W.H.M., VanLoon, L.J.C. (2008). Protein coingestion stimulates muscle protein synthesis during resistance type exercise. American Journal Physiological Endocrinal
Metabolism, 5:70-77.
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