Skip to Content

Is Evolution Selecting for Endurance Runners?

Genetic variation found in elite long-distance athletes boosts efficiency of muscle metabolism.
September 9, 2007

Trainers and athletes already know that sprinters and marathon runners have very different muscles. Sprinters tend to have a preponderance of fast-twitch muscle fibers, which generate short bursts of strength, while endurance athletes have more slow-twitch fibers, which take longer to fatigue.

New research shows that a genetic variation found more often in long-distance athletes seems to make fast-twitch muscle fibers behave more like slow-twitch ones. The variation, known as R577X, completely knocks out a muscle protein expressed only in fast-twitch fibers. Mice genetically engineered to carry this variation had more efficient muscle metabolism and could run 33 percent farther before reaching exhaustion than their normal counterparts, according to findings published Sunday in Nature Genetics.

This variation also seems to confer an evolutionary advantage in humans. By analyzing the DNA sequence surrounding it, scientists found that is has been positively selected for in recent human history.

Keep Reading

Most Popular

Geoffrey Hinton tells us why he’s now scared of the tech he helped build

“I have suddenly switched my views on whether these things are going to be more intelligent than us.”

ChatGPT is going to change education, not destroy it

The narrative around cheating students doesn’t tell the whole story. Meet the teachers who think generative AI could actually make learning better.

Meet the people who use Notion to plan their whole lives

The workplace tool’s appeal extends far beyond organizing work projects. Many users find it’s just as useful for managing their free time.

Learning to code isn’t enough

Historically, learn-to-code efforts have provided opportunities for the few, but new efforts are aiming to be inclusive.

Stay connected

Illustration by Rose Wong

Get the latest updates from
MIT Technology Review

Discover special offers, top stories, upcoming events, and more.

Thank you for submitting your email!

Explore more newsletters

It looks like something went wrong.

We’re having trouble saving your preferences. Try refreshing this page and updating them one more time. If you continue to get this message, reach out to us at customer-service@technologyreview.com with a list of newsletters you’d like to receive.