Building your fast-twitch muscle fibers can help you get stronger and faster. This type of muscle fiber is responsible for the fast, explosive movements used in activities like sprinting, jumping, and ...

Muscle contraction is the tightening, shortening, or lengthening of muscles when you do some activity. It can happen when you hold or pick up something, or when you stretch or exercise with weights.

The muscles powering a sprinter’s explosive start work very differently from those enabling marathon runners to go the distance. Korean scientists have discovered distinct DNA aging patterns in chest ...