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.

When performing a strength training program, people may find it helpful to train certain muscle groups together. This can help prevent overtraining and maximize results. The Dietary Guidelines for ...

Muscle knots are highly irritated muscle fibers that have tightened into a ball in one area of your muscle. These painful, tender spots can feel sore and often occur in your upper back, shoulders, or ...

If you're looking to build muscle, it's important to have patience and also be realistic about how long it will take. Different factors can determine your ability to gain (or not gain) muscle. Muscle ...

The muscular system works to control the movement of our body and internal organs. Muscle tissue contains something called muscle fibers. Muscle fibers consist of a single muscle cell. They help to ...