Repeated exercise, or wasting, can change the way key genes work.

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

The back consists of large, complex muscles that support your trunk and spine. There are many types of back muscles, and they are all essential, helping you walk, bend, twist, and hold your body ...