Have you heard of fast-twitch and slow-twitch muscle fibers? These are the two types of muscle that are responsible for all your gains in the gym. And depending on how you train — and even your own ...

But what if I told you that you don't need to visit a fancy lab or use strange equipment to get an idea of how strong your leg muscles are? That's right! The answer might just be in the most common ...

A muscular, athletic body radiates health and vitality. But how can you really build muscle effectively? FITBOOK takes a closer look at the five most important exercises and shows you how you can ...