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 ...

Your running speed partly comes down to factors you can't control, like genetics, and partly relies on your training. When you purchase through links on our site, we may earn an affiliate commission.

From Hyrox to Pilates, resistance bands and even yoga, experts explain what actually builds muscles – and why it gets harder ...