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 ...

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 ...

Plus, how to get the most of your walking workout.

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 ...

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 ...

Type IIb fast-twitch myofibers, known for their rapid contraction speed, are plentiful in small mammals but have largely diminished in humans. Researchers at the University of Tsukuba have discovered ...