Can training make you a premier long distance runner — or are your abilities determined at birth?

Print Friendly, PDF & Email
Credit: Staff Sgt. Natasha Stannard/U.S. Air Force
Credit: Staff Sgt. Natasha Stannard/U.S. Air Force

All of our skeletal muscles are made up of a combination of two types of fibre: slow-twitch muscle fibres and fast-twitch muscle fibres. 

“Muscles have fibres of both types, but the percentages of each may differ from muscle to muscle and person to person,” says Courtenay Dunn-Lewis, a physiologist at the University of Pittsburgh.

“About 80% of an elite athlete’s muscle fibres are either fast-twitch, if they are a power athlete, or slow-twitch, if they are endurance athletes,” says Dunn-Lewis. “Consider the long, slender physique of a marathon runner, whose predominantly slow-twitch muscle fibres may be small but are resistant to fatigue and provide lasting energy kilometre after kilometre. This person is also burning less energy in a given unit of time.”

Follow the latest news and policy debates on agricultural biotech and biomedicine? Subscribe to our newsletter.

“By comparison, an American football player or hockey player has predominantly large fast-twitch muscle fibres, moves with power and speed, but fatigues quite quickly. Athletes with 80% of one fibre type are simply born lucky. For the rest of us, the percentages are closer to 50% fast-twitch and 50% slow twitch, and that percentage is determined at birth. Fibre type is determined strictly by the nervous system, and for that reason cannot be changed with exercise.”

Read the original post

Related article:  Global plan to halt extinction criticized for failing to address species humans don't like
Outbreak Featured
Infographic: Gene transfer mystery — How 'antifreeze' genes jumped from one species to another without sex

Infographic: Gene transfer mystery — How ‘antifreeze’ genes jumped from one species to another without sex

It isn’t surprising... that herrings and smelts, two groups of fish that commonly roam the northernmost reaches of the Atlantic ...
a bee covered in pollen x

Are GMOs and pesticides threatening bees?

First introduced in 1995, neonicotinoids ...
glp menu logo outlined

Newsletter Subscription

* indicates required
Email Lists
glp menu logo outlined

Get news on human & agricultural genetics and biotechnology delivered to your inbox.