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.
Institute of Human Anatomy - IOHA on MSN

The different types of muscle in your body

Discover the three main types of muscle in the human body and their distinct functions.
Researchers have identified the role of the large Maf transcription factor family in regulating fast twitch muscle fibers. A mouse model lacking Maf expression in the skeletal muscles exhibited a ...