Muscle cramps are painful involuntary spasms of muscles that occur during or immediately after exercise. Muscle cramps can occur almost anywhere on the body and often develop after prolonged or intense use of muscles.
The cause of muscle cramps is not known. One theory is that exercise causes the body to lose too much fluid and salt through sweating. This leads to cramping and is called heat cramps.
A newer theory is that vigorous exercise causes the brain to send constant signals through the nerves to the muscles to contract (tighten). The longer muscles get signals to contract, the harder it is for the muscles to relax. Tired muscles are easily excited and lose some of their ability to rest. Without the balance between contracting and relaxing, muscles can cramp.
Cramping pain often occurs in muscles of the arms, legs, and abdomen. Pain can get worse with continued activity and you may not be able to relax the muscle without help. You may also feel tired and sweat heavily. Cramping is often quite painful and can force athletes to stop play.
Your health care provider will examine you. At the time of cramping, muscles feel firm and tense and may be tender to touch.
You may return to your sport or activity when you have full range of motion and strength without cramping. You should replace lost fluids and salt prior to further activity. Return to sport or activity too soon may result in the rapid return of muscle cramps.
To help prevent cramps, stretch before you exercise. You may also want to stretch during breaks in activity. Make sure you drink enough fluids. Sports drinks may be very helpful. Resting between periods of intense exercise may increase your chances of avoiding cramps.