Okay, so it’s probably not all in the genes, but scientists have begun to track down the genes that are involved in creating runners who run ridiculous distances. Recently researchers in Australia found a mutation that changes muscle structure allowing greater endurance.
I thought mutations were bad, how can one help?
Not all mutations are bad – think the X-men. The X-men are mutants with enhanced abilities. While the X-men are very far from scientifically accurate, the concept is the same. A long time ago someone developed a mutation to enhance endurance and it gave them an advantage (maybe they could out run predators, or run farther to catch prey) so they and their offspring preferentially survived. After many many generations this mutation is now present in about 18% of people of European or Asian descent, and about 10% of people of African descent.
How does this mutation improve endurance?
Muscles have two types of fibers: fast and slow. The fast fibers help people sprint, or perform other tasks that require short bursts of energy. The slow fibers are used for endurance. This mutation is in the gene ACTN3 which encodes a protein made by fast fibers. When this protein is gone, as it is in people with the mutation, the fast fibers act more like slow fibers. Mice with this mutation can run 33% longer than normal mice (ie mice without the mutation).
How do I know if I have this mutation?
Unless your genome has been sequenced (something which may happen in the near future), you don’t. Go for a run and see how you do! Scientists have shown that endurance athletes are more likely to have this mutation, while sprinters are less likely to have the mutation. Which one are you?
THE BOTTOM LINE
No matter what your genes, it takes discipline and mental fortitude more than anything else to be a marathon runner (I should know – I’m sure I’m lacking that gene but am currently training for my third marathon!).
Photo provided by my dad! Can you find me?