Lecture 23 - Nutritional interventions and skeletal muscle Flashcards Preview

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Flashcards in Lecture 23 - Nutritional interventions and skeletal muscle Deck (23):
1

What is the 4 aims in sports nutrition?

To optimise body substrate stores before exercise

To enhance substrate availablilty during exercise and spare muscle glycogen stores

To increase the rate of glycogen synthesis in the recovery phase

To increase muscle protein repair synthesis and reduce muscle damage

2

If there is not a significant difference from nutritional interventions that does not always mean...

that thereis no effect

placebo effects

multiple suppliments

difference between winning and losing can be extremely small

3

True or false

You need food intake to be in a positive protein balance after resistance exercise

true

4

true or false

CHO intake affects protein synthesis

false

CHO intake does not result in a positive protein balance

5

How is CHO thought to interact with the net protein balance indirectly?

Via insulin

The level of insulin that causes protein synthesis is at the very start of release - low levels

will signal GLUT 4, more glucose uptake

Insulin can stimulate the mTOR pathway

potentially more important in regulating MPB

6

The intake of ______ AAs stimualtes protein synthesis

essential

these are the main stimuli to protein synthesis

7

Which signalling pathways does essential AAs use to stimulate protein synthesis?

mTORC1

8

The plateau of protein intake vs. Muscle Protein sythesis rate is at?

about 20-30g

9

True or false

~25g protein is enough to maximally stimulate muscle protein synthesis

true

10

The stimulatory effect of increased AA availability on protein synthesis is how short?

back to basal levels after around 4-6 hours

11

What is the protein makeup of Milk?

3% protein, so 30g/L

80% is casein protein
20% is whey protein

12

True or fasle

Whey protein is more rapidly digested than casein

true

13

AA derived from dietary protein hydrolysate appear quicker in the circulation resulting in...

high protein synthesis

14

Why is Whey protein better than casein?

need to look at the AA composition of the proteins

Whey protein contains much more Leucine

15

Why is Leucine so special?

It stimualtes muscle protein synthesis and inhibits proteolysis

Leucine administration inhibits protein breakdown
- including indirectly through increasing insulin


Leucine can directly stimulate mTORC1 though the Leucyl-tRNA synthase. This enzyme changes GDP --> GTP on the Rags which stimulates the mTOR pathway

16

Recmmended dietary intake represents the ...

minimal intake - not optimal

17

Current American College of sports medicine position stand on dietary practices for athletes recommends protein intake of ....

1.2-1.7 g/kg/day

18

What effect does increased protein intake during weight loss have?

reduces loss of muscle mass

19

Diet and exercise-induce weight loss with higher protein and increased dairy product intakes promotes more favourable body composition changes in women characerised by ...

Greater total and visceral fat loss and lean mass gain

20

_______ is low in protein and represents the biggest opportunity to increase protein intake in frail elderly

Breakfast

21

An issues is that the acute studies into the effects of protein ingestion do not translate into ...

long term studies

Chronic leucine treatment does not increase msucle mass

22

Glycine supplimentation reduces_______________ expression and helps maintain the protein synthetic machinery

Atrogin-1 mRNA expression

23

Metabolism of glycine has a massive effect intracelluarlly on ..

ROS, Glutathoine, changes methylationof DNA,