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

239 genes

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

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

• 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)

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

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

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

50%

30%

• 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

• This is a fat oxidation for slow muscle - it metabolises fat, regular functioning of slow twitch muscle fibres

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

• hypertrophy of the heart and enhances metabolic efficiency

• 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