Nature v Nuture

Question 1

What is the environmentalist approach to sport?

Answer 1

If you selected almost anybody, you can train them in terms of performance to reach a particular level and maybe to even excel in that sport.

Question 2

What is the biological determinism approach to sport?

Answer 2

You cannot achieve sporting excellence unless you have got the right genes for it.

Question 3

Do specific genotypes provide an athletic advantage? Which ones?

Answer 3

Yes:
1. 165 autosomal gene entries
2. 5 on the X chromosome
3. 17 mitochondrial genes

Question 4

What are single genes that can influence athletic performance?

Answer 4

1. Angiotensin converting enzyme (ACE)
2. Insulin-like growth factor (IGF-1)

Question 5

Where is ACE expressed?

Answer 5

In endothelial cells, specifically in the lungs and kidney.

Question 6

What does ACE do?

Answer 6

Converts angiotensin I into II.

Question 7

What does angiotensin II do?

Answer 7

It’s a vasoconstrictor.

Question 8

How does ACE relate to vasodilators?

Answer 8

It breaks down bradykinin, which is a vasodilator, thus resulting in constriction.

Question 9

What is a polymorphism?

Answer 9

A slight variant of a gene.

Question 10

Where are the differences in the polymorphisms of ACE?

Answer 10

In the promoter region, where an insertion of 287 bp can result in lower levels of ACE or a deletion of 287 bp can result in higher levels of ACE.

Question 11

How does higher levels of ACE impact sport performance?

Answer 11

An increase in frequency of ACE in short distance swimmers. This results in increased strength because more angiotensin II is produced, leading to more factors for muscle growth, and thus muscle hypertrophy.

Question 12

How does lower levels of ACE impact sport performance?

Answer 12

There is an increase in the lower levels of ACE in elite distance runners, rowers, and cyclists, which leads to increased endurance. This means less angiotensin II and more bradykinin, thus improved vasodilation, blood supply, and substrate metabolism.

Question 13

What is IGF-1 produced by?

Answer 13

The liver

Question 14

What is IGF-1 stimulated by?

Answer 14

The pituitary growth hormone (GH)

Question 15

How does IGF-1 act?

Answer 15

It acts through the IGF-1 receptor, which is a tyrosine kinase receptor. The receptor autophosphorylates both regions, leading to the recruitment of signalling proteins.

Question 16

What does the stimulation of the IGF-1 receptor lead to?

Answer 16

1. Proliferation of cells via the ERK pathway
2. Protein synthesis, growth, and metabolism via the Akt pathway (hypertrophy of muscle)

Question 17

What determines how much IGF-1 is released by the liver?

Answer 17

Your nutrition state and insulin levels.

Question 18

How does exercise relate to IGF-1 production and release?

Answer 18

1. Environmental and circulating stimuli, including exercise
2. This enhances the release of the GH in the pituitary
3. More GH means more stimulation on the liver to produce/release IGF-1

Question 19

How does IGF-1 relate to neurons?

Answer 19

It has been seen to support neuron growth and survival in the brain.

Question 20

What do the polymorphisms of IGF-1 associate with?

Answer 20

Associated with responses to strength training.

Question 21

What is epigenetics?

Answer 21

The genetic control by factors other than an individual’s DNA sequence.

Question 22

How can epigenetics occur?

Answer 22

Alterations in gene silencing through DNA methylation, histone modification, and RNA associated silencing.

Question 23

What is DNA methylation?

Answer 23

Addition of a methyl group to cytosine.

Question 24

What does DNA methylation regulate?

Answer 24

Transcription

Question 25

How does DNA methylation regulate transcription?

Answer 25

It usually represses gene transcription/expression by methylating the promoter region. It does thus by blocking the ability of transcription machinery to attach to the promoter region.

Question 26

What is hypomethylation? When does it occur?

Answer 26

A reduction in DNA methylation that is induced by exercise.

Question 27

What does PGC-1alpha regulate?

Answer 27

It regulates genes involved in energy metabolism, mitochondrial biogenesis and function, and fibre type determination.

Question 28

What happened to the methylation rates of PGC-1alpha with low and high intense exercise?

Answer 28

With high intense exercise, the methylation rates of these genes is reduced, thus allowing for a greater expression of them. This was seen in an increase in mRNA levels that increased after rest.

Question 29

What is VO2 max?

Answer 29

The measure of maximum volume of oxygen that can be used.

Question 30

What does a higher VO2 max mean with fitness?

Answer 30

The fitter you tend to be.

Question 31

How can VO2 max be increased?

Answer 31

By training, which can relate to genes.

Question 32

How do genetic factors relate to VO2 max?

Answer 32

Genetic factors account for 40% variation in VO2 max before training.

Question 33

What did aerobic exercise result for VO2 max?

Answer 33

An average increase in VO2 max by 19%, but a small cohort (5%) had little to no change.

Question 34

How was the genetic component of VO2 max discovered?

Answer 34

There was a greater variability in VO2 max between rather than within families.

Question 35

What genes affect VO2 max?

Answer 35

1. Positive results in genes like muscle creatine kinase (CKM)
2. A particular DNA sequence variant associated with VO2 max (either high or low responses)
3. Over 97 genes that are involved in lipid metabolism, oxygen delivery, etc.