Protein

Question 1

How many amino acids are there?

Answer 1

20

Question 2

How many essential amino acids are there?

Answer 2

8

Question 3

How many amino acids are oxidised as a fuel?

Answer 3

7

Question 4

Name the 8 essential amino acids?

Answer 4

Isoleucine
Leucine
Lysine
Methionine
Phenylalanine
Threonine
Tryptophan
Valine

Question 5

Name the 7 amino acids that are oxidised as a fuel?

Answer 5

Alanine
Asparagine
Glutamate
Isoleucine
Leucine
Lysine
Valine

Question 6

How is net protein balance defined?

Answer 6

MPS - MPB

Question 7

What is the sedentary protein requirement?

Answer 7

~0.8g/kg/day

Question 8

How is protein balance measured?

Answer 8

Nitrogen balance techniques

Trancer techniques

Question 9

The effects of exercise on protein turnover? (Phillips)

Answer 9

Exercise causes stimulation in protein synthesis
Greater increases in muscle protein synthesis following protein ingestion
Less substantial decreases in protein ingestion

Question 10

What is normal protein turnover? (Phillips)

Answer 10

Both protein synthesis and breakdown follow a sinusoidal pattern
Protein synthesis increases in relation to protein ingestion and decreases over time
Protein breakdown decreases in relation to protein ingestion and increases over time

Question 11

How to design a study to measure muscle protein synthesis?

Answer 11

Resistance exercise (often unilateral and lower body)
Manipulation of post-exercise protein nutrition
Infusion of labelled amino acids in combination with blood and muscle sampling to determine protein synthesis

Question 12

The effect of the timing of protein intake on muscle protein synthesis?

Answer 12

Pre-exercise - positive/no effect in MPS
During exercise - enhance MPS during resistance exercise and early recovery
Post-exercise - impact on recovery?

Question 13

What to take into account to maximise protein synthesis with protein intake?

Answer 13

Body size

Active muscle mass

Question 14

The protein recommendations to maximise net protein breakdown?

Answer 14

Exercise
Consume sufficient energy
Consume sufficient high-quality protein
Consume at least 20-25g every 3-4hrs
Protein intake before bed (30-40g)
Protein intake for breakfast

Question 15

What determines BCAA oxidation rate?

Answer 15

BCAA oxidation rate depends on CHO availability

Question 16

The importance of protein balance on endurance exercise?

Answer 16

Required for mitochondrial biogenesis

Increased requirements for endurance athletes

Question 17

The effect of carbohydrate and protein on muscle glycogen resynthesis? (Reviewed by Betts & Williams 2010)

Answer 17

Increases in CHO increases muscle glycogen resynthesis up to 1.2g/kg/h
When protein is added to CHO to can increase muscle glycogen resynthesis when the rate of CHO intake is sub-optimal

Question 18

What is the protein requirement for endurance athletes?

Answer 18

1.2-1.6g/kg

Question 19

What is the protein requirement for strength athletes?

Answer 19

1.2-1.7g/kg

Question 20

What is the recommended daily protein intake?

Answer 20

90-133g (1.3-1.6g/kg) based on 3000kcal/day

Question 21

What is the suggested protein intake during energy restriction?

Answer 21

Increased protein intake (2g/kg)

Reduces lean tissue loss

Question 22

What is the relationship between athlete protein intake and energy intake? (Van Erp-Baart et al. 1989)

Answer 22

A positive linear relationship between energy intake and protein consumption

Question 23

An 80kg novice male bodybuilder wants to gain 15kg of muscle within 1yr. You have advised him that a more reasonable goal would be 5kg. Calculate how much additional protein would be needed per day in order to achieve these targets assuming the correct level of protein intake (1.4g/kg/day or 112d/day) is achieving nitrogen balance?

Answer 23

15kg
= 15kg x 0.2 = 3kg protein
= 3kg/year = 3000g/year
= 8.2g/day
= 8.2g + 112g = 120.2g
= 120.2g / 80kg = 1.5g/kg/day
5kg
= 5 x 0.2 = 1kg
= 1kg/year = 1000g/year
= 2.7g/day
= 2.7g + 112g = 114.7g
= 114.7g / 80kg = 1.43g/kg/day

Question 24

How much protein is in 1kg of lean muscle?

Answer 24

0.2g

Question 25

A 60kg female endurance athlete is advised that she should be achieving a daily protein intake of 1.2g/kg/day. Analysis of her food intake records indicates that her total daily energy intake is 12kJ and that her protein intake provides 12% of this energy. Calculate her actual intake of protein in g/kg/day. Does she need to supplement her diet with extra protein? You can assume that the energy available from dietary protein is 17kJ/d

Answer 25

Actual
= 12000 x 0.12 = 1440kJ of protein
= 1440kJ / 17kJ/g = 84.7g protein
= 84.7g / 60kg = 1.41g/kg/day of protein

= No she does not need to supplement with extra protein because she’s consuming above 1.2g/kg/day of protein

Question 26

In the study by Josse et al. (2010), 2 groups of underwent 12wks of progressive resistance exercise. One group received 1L semi-skimmed milk and the other 1L of CHO solution. The semi-skimmed milk group gain 1.9kg of lean mass and lost 1.6kg of fat mass. From these values estimate the average energy balance that subjects experienced. Also, estimate this as daily energy balance? You can assume the energy values of 38kJ/g of fat and 17kJ/g protein

Answer 26

Fat = 1600g x 38kJ = 60800kJ
Protein
= 1.9kg x 0.2 = 380g
= 380g x 17kJ = 6460kJ
Energy Balance
= 60800kJ - 6460kJ = 54340kJ
= 54340kJ / 84days = 647kJ/day

= energy balance is -647kJ/day

Question 27

Which of these is an essesntial amino acids is branched?

• lysine
• valine
• threonine
• histidine

Answer 27

Valine

Question 28

What is the effect of resistance exercise on MPS and MPB?

Answer 28

Increases MPS and MPB

Question 29

Leucine appears to potentiate MPS through stimulation of?

Answer 29

Mammalian target of rapamycin (mTOR)