Wk 6 Protein Flashcards
Essential AAs - BCAAs
Leucine
Isoleucine
Valine
Essential AAs - other
Histidine Lysine Methionine Phenylalanine Threoine Tryptophan
Nonessential AAs
Alainine
Aspartic acid
Cysteine
Glutamic acid
Conditionally essential AAs
Arginine Asparagine Glutamine Glycine Proline Serine Tyrosine
Fate of protein (3):
- Incorporated into body protein or used to make other nitrogen-containing compounds eg nonessential AAs
- Be oxidized for energy;
- Undergo deamination = removal of nitrogen group - converted to urea and excreted from the body in urine
- Carbon skeletons enter Krebs cycle at many different points - Contribute to the body’s glucose, ketone and lipid pool
Protein functions
Structure and motion - collagen, keratin, contractile fibers of muscle.
Transport - hemoglobin.
Chemical messaging - hormones.
Catalysis - enzymes. Immune function - antibodies.
Protein anabolism vs catabolism
Anabolism: synthesis > breakdown
Catabolism: synthesis < breakdown
Protein RDA
0.84 g/kg/day
Adolescent growth spurt -
Boys gain _mg protein/kg body weight/d.
50
Long vs short term effects of protein supplements
- Short term: no apparent relationship between recovery of muscle function and ratings of muscle soreness and markers of muscle damage when protein supplements are consumed prior to, during or after about of endurance or resistance exercise.
- Longer term: as the period of exercise and supplementation is extended over several days and weeks, surrogate markers of muscle damage and ratings of muscle soreness are reduced when protein is provided before, during and/or after exercise.
_ and _ are primary fuels for exercise, _ may contribute small amounts
CHO and fat, protein
Protein contribution during exercise
Usually 2%. Large amounts (5%) may be used during prolonged exercise >4 hrs, especially when glycogen depleted (gluconeogenesis increases). Most efficient solution for most athletes is to make carb available.
How much protein can we absorb?
0.25-0.3 g/kh per meal, especially in recovery.
Plant food consumption results in…
more urea production and more AA oxidation.
Protein recommendations for athletes
ACSM/ADA/DC position: 1.2 - 2 g/kg/d - generally 1.6 g/kg. Higher intakes may be indicated for short periods during intensified training or when reducing energy intake. Consume 0.25/0.3 g protein/kg/eating occasion approx every 3 hours, shortly after exercise, casein protein source before bed. Recommendations based on high quality animal sources, plant based athletes require slightly higher intakes.
