Everyone is familiar, at least hand-wavingly, with the distinction between slow-twitch and fast-twitch muscle-fiber types. The former are great for running marathons; the latter are ideal for ...

Ever wonder why some people seem to pack on muscle effortlessly while others spend months in the gym with little to show for it? Muscle growth isn't just about lifting weights -- it's a complex ...

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 ...

When you picture different athletes – marathon runners, gymnasts and Olympic weightlifters, for example – you likely categorise them instinctively by their height, size and build. But what makes these ...

Usain Bolt, the world’s fastest person, ran a 100-meter sprint at a speed of 23.35 miles per hour (37.57 kilometers per hour). That’s mind-blowingly fast for a human. It’s about the same speed as ...