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.

If your fitness goal is to up the ante on endurance, pack more power into your sprint, or supercharge your strength gains in the gym, it’s worth exploring – what are the different muscle fiber types?

Skeletal muscle is the type of muscle that controls movement. Problems with these muscles can be minor, life-threatening, or ongoing problems that make it hard to perform basic daily activities.

Cardiac muscle tissue, or myocardium, is a type of muscle tissue that forms the heart. It contracts and releases involuntarily and keeps the heart pumping blood around the body. The human body ...