Protein

Question 1

protein turnover during resistance & endurance training

Answer 1

• resistance: AA’s are recycled
• Endurance: AA’s are decayed

Question 2

____ increases in both resistance & endurance exercise BUT without protein ingestion ___ also increases

Answer 2

MPS
MPB

Question 3

AA use decreases when

Answer 3

• consumption of CHO during ex
• usage rates still higher than at rest though

Question 4

AA use increases when

Answer 4

• greater ex. intensity &/or duration
• low mus. glycogen availability
• high protein diet (> 1.8g/kg)

Question 5

extra AA are used as:

Answer 5

• substrates for gluconeogenesis
• directly as fuel in the mus. mitochondria

Question 6

how much energy is used during AA metabolism

Answer 6

2-6% during aerobic exercise
- may increase to 10% with low CHO

Question 7

extra energy (usually ___) helps muscle recovery after ex. by maximising _________

Answer 7

CHO
glyc. resynthesis

Question 8

protein dose after ex. , optimal bolus & after endurance training

Answer 8

• 20g of high-quality prot. maximally stimulates MPS
• extra protein used for energy or lost in urine
• optimul bolus = -0.3g (maximises MPS & minimises AA oxidation)
• dietary AA’s used for repair & remodelling
• after endurance, prot. req may be higher to enhance muscle remodelling and recovery and replenish exercise-induced oxidative losses

Question 9

protein timing:
before, during and after ex.

Answer 9

before: no benefit
during:
- -ve whole body prot. balance
- intake during decreases use of internal AA’s as a fuel source -> improves whole-body prot. balance -> post-ex. prot. can be used for mus. prot. remodelling
- MPS may be increased when prot. is injested & rest is long enough
After:
- effect of ex. (esp RT) long lasting <24 hrs
- pattern crucial
- 20g every 3 hrs better than 10g every 1.5 hrs or 40g every 6 hrs for myofibrillar prot. syn.
- double dose i.e. 0.6/kg before sleep can increase mus. prot. remodelling overnight

Question 10

dietary protein sources

Answer 10

• isolated soy & animal-based protein > than plant-based for essential AA
• prot. enriched in AAs (& esp. leucine) & rapidly digested -> higher prot, scores -> rapid rise in MPS after ex.
• nutrient & protein-dense
• isolated prot. supps may help intake & distribution (also good for vegans)

Question 11

protein requirements: general pop, RT athletes & endurance athletes

Answer 11

Gen: 0.8-0.9 g/kg/d (spread evenly)
RT: 1.7 g/kg/d (4 x 0.3 g/kg meals/d + 0.5 g/kg pre-bed
E: 1.9 g/kg/d (3 x 0.3 g/kg meals/ d + 0.5 g/kg post-training + 0.5 g/kg pre-bed meal)

Question 12

higher pro. diets: are they a health risk?

Answer 12

• potentially not
  BUT
• may displace other nutrients
• cost may be higher
• pot. higher acidic load on body

Question 13

to increase energy intake for muscle growth:

Answer 13

• increase no. of meals instead of size
• use energy-dense drinks & foods - commercial liquid meal supps also useful

Question 14

Weight gain goals

Answer 14

• 0.25 - 0.5 kg/wk appropriate
• faster gains may cause body fat increase
• must be realistic - athletes are unlikely to increase mus. mass and decrease body fat simultaneously
• 1500-2000 kJ increase
• plan & prep