Lecture 14

Question 1

The plasticity of skeletal muscle tissue is attributed to 2 dynamic and continuous processes that take place throughout the day. Name them

Answer 1

Muscle protein breakdown and synthesis

Question 2

T or F: Skeletal muscle is a plastic tissue and is constantly “turning over”

Answer 2

TRUE

Question 3

T or F: Skeletal muscle hypertrophy is governed by ___

Answer 3

Net protein balance (MPS vs MPB)

Question 4

What happens if you increase both MPB and MPS when you exercise?

Answer 4

If you don’t have a protein meal after exercise you get more MPB than MPS so risk of injury increases

Question 5

What is mTOR?

Answer 5

Mechanistic Target Of Rapamycin

Question 6

increase in mTOR activity comes from 3 options

Answer 6

Resistance exercise
Amino acids
Growth factors

Question 7

Increase in mTOR activity leads to what effect on MPS?

Answer 7

Increase in MPS

Question 8

Increase in MPS leads to what consequence for the muscles?

Answer 8

Hypertrophy

Question 9

Mechanism to activate synthesis: when there is food vs no food

Answer 9

Need specifically amino acids from proteins or you can’t get MPS because you will get the energy from the muscle = increase in MPB

Question 10

Where does the energy comes from when you have not gotten any proteins in?

Answer 10

Get MPB from the muscles

Question 11

Is it possible to gain muscle while loosing weight?

Answer 11

Yes, but the window is very small = minimal calorie deficit

Question 12

When you loose weight, is it normal to loose muscle mass?

Answer 12

Yes normal phenomenon

Question 13

Where do you get the essential amino acids vs non-essential?

Answer 13

Essential: get it from the diet
Non essential: can synthesize them

Question 14

Name the 9 essential amino acids

Answer 14

Histidine
Isoleucine
Leucine
Lysine
Methionine
Phenylalanine
Threonine
Tryptophan
Valine

Question 15

Muscle protein is ____ slower turnover compared to other organs

Answer 15

20x

Question 15

Muscle protein accounts for ___ of protein metabolism in the body

Answer 15

30%

Question 16

What molecule do you need to stimulate to increase MPS?

Answer 16

mTORC1

Question 17

Can you get an exact measurement of protein synthesis if you get it from the blood?

Answer 17

No, because it happens in the muscle but also in:
- plasma
- urine
- saliva
- CO2

Question 18

The liver extracts a portion of the AA, letting ___ of AA we ingest into the circulation

Answer 18

30%

Question 19

AA are used for 3 things

Answer 19

1. Used for protein synthesis
2. Converted to other amino acids
3. Oxidized

Question 20

Nutritional recommendations for proteins - Adult

Answer 20

0.8-1.0 g/kg of BW

Question 21

Nutritional recommendations for proteins - Elderly

Answer 21

1.2 g/kg of BW

Question 22

Nutritional recommendations for proteins - Athletes

Answer 22

1.2 g/kg of BW

Question 23

Why do elderly need more proteins?

Answer 23

Anabolic resistance - decrease in protein assimilation

Question 24

How do you measure anabolic resistance?

Answer 24

You measure protein synthesis using stable isotopes

Question 25

Maximum protein resynthesis rate

Answer 25

25-30g

Question 26

When can we have high MPS and also MPB?

Answer 26

When we exercise - specifically eccentric training

Question 27

What happens to MPS if you eat more than 30g of proteins in a single meal?

Answer 27

PLATEAU

Question 28

The type of proteins consumed will affect what (2)

Answer 28

Tissue repair Muscle mass gain

Question 29

T or F: Whey protein contains all essentials AA

Answer 29

TRUE

Question 30

Proteins recommendations for endurance athlete

Answer 30

1.2-1.4 g/kg of BW

Question 31

Proteins recommendations for power athlete

Answer 31

1.4-1.6 g/kg

Question 32

3 possible consequence of excess of proteins

Answer 32

Kidney overload Excess weight Adipose tissue

Question 33

Difference between BCAA and complete protein in the MPS

Answer 33

Complete protein stimulates MPS much longer

Question 34

What is BCAA

Answer 34

Branded-chain amino acids

Question 35

What are the 3 BCAA

Answer 35

Leucine Isoleucine Valine

Question 36

Amount of protein needed to stimulate MPS for the young vs the elderly

Answer 36

20g young 40g elderly

Question 37

in the hours following a workout, MPS is approximately ____ to ____ higher

Answer 37

100 to 150%

Question 38

Factors influencing synthesis - Acute dietary factors (4)

Answer 38

Protein dose Protein EAA content Mixed meal co-ingestion Alcohol

Question 39

Factors influencing synthesis - Chronic dietary factors (3)

Answer 39

Protein intake Fish-oil intake Energy intake deficiency

Question 40

Factors influencing synthesis - Non-dietary factors (7)

Answer 40

Resistance type exercise Physical inactivity Aging Female sex (pre-menopause) Female sex (post-menopause) Lean mass Fat mass

Question 41

T or F: you can't get all the essential amino acids from being vegan

Answer 41

FALSE (ex: tofu, chickpeas)

Question 42

Does getting protein from an animal source necessarily correlates with muscle mass?

Answer 42

No, herbivorous animals are strong (ex: elephant, giraffe, bison, hippopotamus, rhinoceros, horse)

Question 43

In the study that compared 3 strategies (bolus, intermediate, pulse) to assess the impact of timing and distribution of protein intake, what was the conclusion?

Answer 43

Winner is intermediate = get at least 20g of protein to get protein synthesis - long term would be the most beneficial

Question 44

Recommendation for pre-sleep protein ingestion

Answer 44

40g of protein before sleeping to increase protein synthesis

Question 45

Consequence of pre-sleep protein ingestion in resistance athletes

Answer 45

Increase in overnight fractional synthetic rate (FSR)

Question 46

2 impacts of carbohydrates on muscle protein synthesis?

Answer 46

Insulin impacts muscle growth Carbs + proteins = increase in insulin but no further increase in MPS

Question 47

Does the timing of protein intake affect mass gain?

Answer 47

Study says no, as long as the daily protein consumption is achieved