Here are a few key points regarding the use of protein supplements: - Protein supplements can be useful for athletes and individuals who struggle to meet their daily protein needs through diet alone. They provide a convenient way to boost protein intake. - However, protein supplements should not replace whole foods as the primary source of protein. A diet with a variety of protein-rich foods is ideal for overall nutrition. - The research on whether protein supplements can further enhance muscle protein synthesis beyond what can be achieved through diet alone is mixed. For most active individuals, meeting protein needs through food is sufficient. - Whey protein in particular has research showing it can modestly increase muscle protein synthesis after exercise compared to casein or soy protein.

1. MODULE 6 - PROTEIN &
EXERCISE

2. PROTEINS
Amino acids linked by peptide chains for
proteins
The body requires 20 different amino acids
• alanine, arginine, asparagine aspartic acid, cysteine, glutamine, glutamic
acid, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, prol
ine, serine, threonine, tryptophan, tyrosine, valine

3. Complete vs Incomplete Proteins
Complete - Contain the essential amino acids in the right ratio to
maintain nitrogen balance and allow tissue growth & repair.
Incomplete - Lacks one or more essential amino acid

4. Roles of Protein
1. Protein in nervous and connective tissues do not participate in
energy metabolism
2. Amino acid alanine Plays a key role in providing CHO fuel via
gluconeogenesis during prolonged exercise
3. During strenuous exercise of long duration, alanine - glucose
cycle accounts for 40 - 50% of liver's glucose release.

5. PROTEIN UTILIZATION
• Protein utilization depends on how well the total energy
expenditure is met by the intake of food
• Inadequate total energy intake forces the athlete to burn
protein
• This depletes muscle protein which is not desirable
• Protein requirement is about 20% of total calorie intake OR
1.2 to 1.7g/kg body weight

6. a) PROTEIN REQUIREMENT FOR
ENDURANCE AND RESISTANCE EXERCISE

7. Protein Requirement for Endurance
Exercise
Endurance training might need about 1.2 to 1.6 g x kg(-1) x day(-
1) (approximately 1.5 times the current RDA)
Serious endurance athletes need protein above the normal adult
RDA for:
• maintenance
Of LEAN MUSCLE
• growth
• repair
• optimum immune system function

8. Not providing sufficient
protein will lead to lethargy,
anaemia and will cancel
beneficial effects of
exercise.
In fed individuals protein is meant to contribute 1-8% to
the energy expended depending on the sex and the
duration of the athletic competition.

9. • Protein is used in prolonged, continuous, moderate to
intense activity (endurance)
• 5-10% of the energy needs for endurance exercise (>90
minutes) may come from protein.
• Protein synthesis is suppressed during exercise and
stimulated when physical activity ends.
• Endurance exercise appears to improve the efficiency of the
body to utilize nitrogen.
• Amino acids are used to repair muscle trauma that results
from repeated muscle contractions and eccentric
contractions in particular.

10. Activity:

12. Protein Requirement for Strength Exercise
Those involved in strength training might need to consume as
much as 1.6 to 1.7 g protein x kg(-1) x day(-1) (approximately
twice the current RDA)
Extra protein is needed by strength-trained athletes to repair
injuries to muscle fibers and to remodel muscle tissue in
response to strength training.

13. • High intensity, intermittent activity that incorporates
strength training in the exercise program.
• Resistance exercise provides the stimulus for gains in muscle
size and strength.
• Strength training relies on anaerobic metabolism for energy
production. The primary fuel for resistance exercise is muscle
glycogen.
• Building muscle is energy intensive.

14. b) PROTEIN TURNOVER IN EXERCISE

15. PROTEIN TURNOVER
• Protein turnover (synthesis and degradation) is elevated in
strength athletes.
• Protein requirements are increased to supply amino acids to
maintain nitrogen balance and to support enhanced rates of
protein synthesis.
• Protein turnover depends on the following factors
1. Exercise intensity
2. Exercise duration
3. Training state
4. Energy consumed
5. Gender

16. Exercise Intensity
Exercise intensity affects the protein turnover directly, based on the
example shown above.

17. Exercise Duration
During long duration of exercise there is more break down of protein
resulting in the increase of by products of amino acid oxidation.

18. ... to put this in perspective
For example, a person who cycles for 60 minutes
in a glycogen depleted state might use as much
as 2.4 times the amount of protein as those with
high initial glycogen levels.

19. Training State:
• Protein turnover with endurance exercise.
• Protein turnover when there is sufficient energy from
glycogen.
Protein-sparing action of carbohydrate
When there is an adequate intake of carbohydrate, the body
does not need to metabolize muscle protein for energy.
Ensuring the energy requirement is met by carbohydrate is vital
to preserve the protein in the body

20. c) BCAA AND FATIGUE

21. BCAA AND FATIGUE
Branched chain amino acids - Leucine, isoleucine, valine
Serotonin plays a role in the central mechanisms of fatigue
Serotonin is produced from tryptophan
Tryptophan is usually found in the blood bound to albumin or as
free tryptophan
The amount of free tryptophan that crosses the blood brain
barrier depends on the concentration of BCAA.

22. Mechanism - BCAA and Fatigue
During long duration exercise fat is broken down to produce
energy as a result of which fatty acids are formed.
These fatty acids bind to albumin thus reducing the number of
albumin binding sites for tryptophan.
At the same time exercise leads to the breakdown of BCAA which
causes an imbalance in the tryptophan:BCAA ratio.
An increase in this ratio causes the free tryptophan to cross the
blood brain barrier and INCREASES the amount of SEROTONIN
leading to FATIGUE

23. What does 100 grams of protein look like in food?
Food Amount Protein (grams)
Raisin bran cereal 2 cups 10
1% milk 2 cups 16
Bread 2 slices 5
Chicken breast 1 large 19
piece
Swiss cheese 1 ounce 8
Lean steak 1 34
Baked potatoes 1 med 5
Broccoli 1 cup 6
Egg white 1 3.6

24. d) PROTEIN SUPPLEMENTATION

25. PROTEIN SUPPLEMENTATION
Many use protein supplements believing that they enhance
performance by way of increasing the production of anabolic
hormones.
Some research shows that there is no significant effect of amino
acid supplements on the
1. Hormone secretion
2. Training response
3. Exercise performance
However, this is a debatable topic and pros and cons will be
discussed.

26. Effect on Hormones

27. Whey Protein
Whey protein is the protein contained in whey, the watery portion of milk that
separates from the curds when making cheese.
Whey protein is used for improving athletic performance, as a food supplement, as an
alternative to milk for people with lactose intolerance, for replacing or
supplementing milk-based infant formulas, and for reversing weight loss and
increasing glutathione (GSH) in people with HIV disease.
Contraindication:
Uses:
Whey taken in regulated
In conjunction with strenght quantities does not have any
training whey improves: known side effects.
1. Lean muscle mass If taken in excess can lead to:
2. Strength
3. Muscle size 1. Nausea
2. cramps
3. Fatigue
4. Reduced appetite

28. Casein
Casein is the main protein in milk. It is the ingredient in milk that
solidifies when milk curdles. When people drink
milk, digestive juices break down the casein into protein
pieces called casein peptides
Side-effects:
Benefits:
1. Rashes
1. Improved muscle Mass
2. Bloating,
2. Great Muscle retention
3. Hives
3. Greater fat loss
4. Stomach aches
4. Helps increase energy
and cramps
5. Improves stamina
5. Gastro-intestinal
discomfort

29. L- carnitine
CONS:
PROS:
Some research shows :
1. Acts as a vasodilator in
peripheral tissues 1. No ergogenic effect
2. May enhance regional blood 2. Does nto increase
flow & oxygen delivery anabolic processes
3. Improves oxygen supply to 3. No improvement in
damaged tissue - May improve performance
DOMS - delayed onset muscle
soreness 4. No enhanced recovery

30. Creatine

31. Creatine Benefits:
Creatine Risks:
Not many risks have been
documented after creatine
supplementation.
Short term use in healthy
men has had no detrimental
effect on blood pressure and
renal function.
Individuals with poor kidney
function should refrain from
taking this supplement.

32. Activity:
Interpret the following graph with regards to Total Creatine.

33. Discussion
Your thoughts on the use of protein supplements