40. Genes and Training

Question 1

What is the role of skeletal muscle

Answer 1

Locomotion

Respiration

maintenance of glucose homeostasis

Question 2

At what age does skeletal muscle start to decline

Answer 2

Around 40

Question 3

What is the range of muscle mass in individuals?

Answer 3

12 and 41kg- woman

15 and 54kg- male

Question 4

What two factors relate to cross sectional area?

Answer 4

Number of fibres in the muscle- (very important)

Muscle Fibre Size - (still important)

Question 5

How much of an impact does heritability have on muscle mass?

Answer 5

around 50%

Question 6

Discuss the impact myostatin has on muscle mass?

Answer 6

Inhibitor of muscle development. When knocked out in mice/bulls there are around 80% more fibres that are 15-50% larger

Not very applicable in humans

Question 7

What is meant by reverse genetics?

Answer 7

Research that looks from gene to effect

This is different to forward genetics that looks at a wide range of phenotypes and genetic differeneces

Question 8

What is a manhattan plot

Answer 8

Not sure need to google

Question 9

Explain the impact POU34 gene can have on muscle mass

Answer 9

In mice incerasing Alleles have been shown to increase fibres within muscles

Humans without POU34 are more likely to have systemic deafness as well as reduced reduced muscle mass. However it is not relevant in prime health

Question 10

What can be said about how muscle mass is affected in the elderly?

Answer 10

You can group them into categories due to decreasing alleles that are associated with msucle mass

Quantile 1 are more associated with sarcopenia but it is due to a wide range of genes

Question 11

What can be said about ARG44LEU and its affects of muscle mass

Answer 11

STC2 coding gene- when mutated increases muscle mass

STC2 is a competitive inhibitor of Pappa-A which causes the release of IGF-1

When it is inhibited IGF-1 increases

Question 12

Explain the affects that ACTN3 has on muscle mass

Answer 12

ACTN3 is a component of Z lines.

Results in a premature stop codon leading to different expression of ACTN (2) typicaly found in type 1 fibres, making the fibres slower

Despite being shown to be reduced in power lifters, doesnt have much of an effect on function.

Question 13

What has previous studies shown about responses to training

Answer 13

Bell curve of response.

Some are high responders (<10%) ,
some are non-responders (<10%)

When putting different mice under swimming stress they were able to show some reponded better than other

Question 14

How does fibre proportion vary?

Answer 14

Type I fibres can vary between 20 and 80%

Question 15

What fibres can hypertrophy to greater effects?

Answer 15

Type II fibres hypertrophy much larger than type I

Question 16

What else can vary between individuals that would explain a difference in CSA gain after exercise?

Answer 16

protein synthesis rate can vary between individuals

Question 17

How is the ACE gene related to gains in performance

Answer 17

Those who have two indel? alleles for the ACE gene they can increase their reponses to training much greater

Question 18

How does increased angiotensin conversion enzyme increase response to training

Answer 18

Hypothesised to affect growth of cells, demonstrated to affect left ventricular mass

Still poorly understood

Question 19

Why is talent rare

Answer 19

Talent is a combination of many many genes and the individuals who have all of the certain genes are very limited

Human population statistically cannot have the ideal athelte due to the unliklehood of the chance.