If you didn’t already know you have different types of muscle fibers in your body, now you do. And depending on how you exercise or what sports you enjoy, you’re building and recruiting some ...

You can’t train in middle age like you did in your 20s. But if you’re strategic, your best days can still be ahead.

Former NFL pro Roman Fortin is helping his clients strengthen their "Fast Twitch" muscles—the muscle fibers we use when doing short, intense—more exertive activity. Problem is these types of ...

Another thing that can influence how well you put on muscle are your fast-twitch and slow-twitch muscle fibers. Skeletal muscles are composed of both of these fibers, which serve different ...

Chimps possess about twice the amount of "fast-twitch" muscle fibre. This type of fibre contracts quickly and is useful for rapid movements such as sprinting. But fast-twitch fibres have a ...

“We all have slow and fast-twitch muscle fibres,” she says. “Fast-twitch muscle fibres are used for power and strength – high-intensity movements or exercises – and grow faster and bigger.

Stress occurs whenever you work your body harder than it's used to — like when you hit the pavement while ... fibers in the body: slow-twitch muscle fibers and fast-twitch muscle fibers.