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 ...

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 ...

Most fitness-minded people have probably heard of fast- and slow-twitch muscle fibers. However, the distinction can be somewhat mysterious, especially in the context of understanding how it relates to ...

If you’ve ever wondered why some people seem to adapt more quickly to resistance training, it’s probably due to the type of skeletal muscle tissue they have. Each of our muscle fibers is either ...

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 ...