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 ...

The misconception that muscle can be lean or bulky lies in its appearance. “When people (say ‘lean’), they’re usually ...

There are a bunch of different reasons that serious endurance athletes generally don’t have big pipes. The most obvious one is that they spend a lot of time running and pedaling and so on, and very ...

High-Intensity Interval Training (HIIT) has become one of the most effective fitness strategies in the United States for ...

Beginner runners sometimes feel like their legs are heavy, as if they don’t have the strength to push off from the ground in order to get some speed. Of course, the more they run, the less this ...

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.

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 ...