Lecture 10 - Genetics in Health-related Physical Fitness and Performance

Question 1

How many gens have been found to relate to physical fitness and performance?

Answer 1

239 genes

Question 2

What are the health-related physical fitness and performance phenotypes

Answer 2

• Cardiorespiratory fitness
• Heart rate, blood pressure, blood size
• Endurance performance
• Muscle size, strength and endurance
• Body Composition
• Blood lipids, carbohydrate metabolism

Question 3

Is VO2max determined by your genes

Answer 3

VO2max depends on a large number of phenotypes associated primarily with functions of the heart, blood vessels and lung

Question 4

What is trainability

Answer 4

• the extent of change in a phenotype with exercise training
• for the same exercise physical activity regimen for 15-20 weeks - there is a 3-10 fold difference between high responders (large improvement) - the extent of variation depends on phenotype measured
• 75% of this variation in response to regular exercise cannot be explained (pre-training levels account for 10-25% of the variation improvements)

Question 5

Genes and muscle function rates

Answer 5

• 40% heritability for muscle strength
• 20-40% heritability for muscle endurance
• 50% muscle fibre type composition (% type I)

Question 6

Describe fast muscle fibres

Answer 6

• light (fast type 2)
• stronger - sprint
• good at developing tension in short space of time

Question 7

Describe slow muscle fibres

Answer 7

• Dark (slow type 1)
• work longer - endurance
• not good at generating tension in short space of time

Question 8

What percentage of variation in blood lipids and lipoproteins between individuals

Answer 8

50%

Question 9

What % is adult activity level is genetic

Answer 9

30%

Question 10

What are some limitations/issues

Answer 10

• tests only a few genes - physical performances is influences by several genes, and more genes than we know about and other factors including physical activity/exercise and training, nutrition
• ethical issues when a wide range of genes could be screened

Question 11

What are PPARs

Answer 11

• This is a fat oxidation for slow muscle

- it metabolises fat, regular functioning of slow twitch muscle fibres

Question 12

What is ACTN3

Answer 12

• provides information to make protein to regulate fast twitch muscle fibres - increased endurance and sprinting ability

Question 13

What is ACE

Answer 13

• hypertrophy of the heart and enhances metabolic efficiency

Question 14

What is GDF - 8

Answer 14

• A negative muscle growth regulator
• Contains Myostatin - a hormone/protein to control heart muscle growth - break on the growth
  –> less myostatin = bigger muscles
• regulates how many muscle fibres there are and the number, size and type (more fast twitch/ type2)
  NOTE - if you have a mutation, then you lose control on the muscle growth