What's the first thing that comes to mind when you think about the words twitch and muscle? Spasms, perhaps. You'd hardly be alone in thinking that. But when it comes to fitness, it's most commonly ...

This article was originally featured on The Conversation. Usain Bolt, the world’s fastest human, ran a 100-meter sprint at a speed of 23.35 miles per hour (37.57 kilometers per hour). That’s ...

Tsukuba, Japan—Muscle fibers, which constitute skeletal muscle, are classified into two main types: slow-twitch (Type I, red muscle) and fast-twitch (Type II, white muscle). Slow-twitch fibers are ...

A woman smashed a longstanding world record in the 200-meter sprint at the age of 91, prompting scientists to delve into her physiology to learn how she can run so fast. Researchers will present their ...

Women's Health may earn commission from the links on this page, but we only feature products we believe in. Why Trust Us? Picture this: You’re training for a race and have been determined to knock a ...