Paul T, from Kingston 6, asks Checkup what makes black athletes run faster.

Yes, black athletes are running faster than any other race on planet Earth and there does seem to be an explanation. Ninety-eight per cent of the 100m male record holders have been black! There are several reasons given for this.

Research has shown that physical differences in leg length and body build reveals that blacks, on average, have a higher centre of gravity. Blacks, tend to have longer limbs which means their centre of gravity, on average, is higher than most other races. Because of the laws of physics even this small difference makes a difference in a short 100 metre race.

Leg height (length) impacts positively on runners as this shifts the centre of gravity higher up resulting in faster running. It also allows for a longer stride. It is the legs that run, not the body (trunk), so races tend to be won by individuals with shorter bodies and longer legs!

Most of the fastest runners (sprinters) in the world can also track their genes back to West Africa. It is thought overall that an athlete's environment accounts for only 25 per cent of athletic ability and all the rest is genetically coded. Western and Central Africa ancestry allows for thousands of years of evolution to 'run fast'. Characteristics such as skeletal muscle, distribution of muscle fibre types (sprinters have more 'fast-twitch' fibres), metabolic efficiency and lung capacity are often genetically determined.

Recently, a 'speed gene' has been isolated, ACTN3. This gene makes fast twitch muscles twitch faster! Scientists now speculate that it is almost impossible for someone lacking this gene to become a sprinter! It would seem that sporting ability is the result of several genes that are influenced by environmental triggers (like training).

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