Protein and Exercise Flashcards
Why else is protein important?
Repair muscle damage
Replacement- around 5-15% of amino acids are burned during exercise
Why is protein important?
Energy production- amino acids converted to glucose
Amino acids can be sorted as fat
Amino acids an be metabolised to produce ATP
proteins control amphoteric (blood pH)
Enzyme production
Transport of fat
Hormone production- insulin and serotonin
Proteins from antibodies
What happens to excess proteins?
Broken down and excreted as nitrogen
Energy production
Metabolically converted and stored as glycogen fat
1st phase of digestion
Begins in the stomach
HCL breaks down pepsinogen to pepsin
Pepsin activity terminates in the small bowel
2nd phase of digestion
Chyme in the intestine
Pancrease secreates protease:
Endopeptidases
Exopeptidases
Trypsinogen
How are free amino acids absorbed?
Sodium binds to carrier protein
Amino acid binds to carrier protein
Carrier protein release sodium and the amino acids inside the enterocyte
How to measure protein?
- Nitrogen balance
Amount of nitrogen consumed in balance against the amount excreted - Marker compounds
Urea
3-methylhistidine- product of myofibrilar protein breakdown - Stable isotope techniques
13c , 15n or 2h are infused intravenously
Using mass spectrometry the level of isotope enrichment is measured
Protein and post-recovery
Proposed that consuming a protein rich meal after exercise has synergic effects
May induce muscle protein synthesis
Leucine in particular, thought to be potent stimulator of MPS
Protein requirements?
15-20% of total energy intake
4kcals per gram
0.8kg day moderate
1.4-1.8 kg day ultra endurance
Ramifications of high protein diet
Excessive levels exceed livers ability to convert nitrogen to urea
Hyperammonemia
Diarrhoea
Dehydration
