10. Protein Functions
• Tissue building: important for athletes trying to put
on muscle mass.
• Cell functioning
– Enzymes
• Body functioning
– Hormones
– Immune function
– Fluid balance
• Energy source: prefer not to use protein as energy
source but if athlete isn’t taking in enough calories
then protein will be diverted from other important
functions to be used for energy.
11. What is nitrogen balance?
Nitrogen balance is an indicator of nitrogen
status and thus protein intake.
Equals: (Nitrogen in) – (Nitrogen out)
13. Factors Influencing Protein Requirements
• Total energy intake
• Desire to lose or gain weight
• Carbohydrate availability
• Exercise intensity and duration
• Training status/fitness level
• Dietary protein quality
• Age
15. Questions to Ask About Protein
Supplements
• What is the quantity of protein or amino
acids in the product?
• Is the supplement necessary?
• What is the cost?
• Will it enhance performance?
• Does the supplement have any harmful
effects?
17. How much protein should be consumed
4 to 24 hours before competition?
• Depends on how much time before exercise
is initiated
• Lean protein sources
– 3 to 6 oz turkey, fish, soy
or
– 8 to12 fl oz dairy
or
– Complementing low-fiber plant sources
18. How much protein should be consumed
1 to 4 hours before competition?
• Focus should be on CHO
• Small amounts of protein okay (i.e., 2–4 oz lean
meat)
• Lean protein sources preferable
19. What about protein consumption during
competition?
• Protein can serve as an
energy source.
• Consumption during
exercise is
questionable.
• There is some research
support for branched
chain amino acids
during competition.
20. What about protein consumption after
competition?
• 6 to 20 grams of high-quality protein
– Casein
– Whey
– Soy
• Essential amino acids are key.
• Should be consumed within 3 hours after
competition.
• Hydrolyzed protein sources are absorbed more
quickly.