Leg cramps occur when the muscle suddenly and forcefully contracts. The most common muscles to contract in this manner are muscles that cross two joints. These muscles include the calf (crossing the ankle and knee), the hamstring (crossing the knee and hip), and the quadriceps (also crossing the knee and hip).
Leg cramps usually last less than one minute, but may last several minutes before the contraction subsides. In some patients, the leg cramps occur primarily at night, and can awaken the patient from sleep.
What causes a leg cramp?
The exact cause of a leg cramp is not well understood, but there are some risk factors that are thought to contribute to this condition:
- Muscle fatigue
- Heavy exercising
- High weight (not necessarily obesity)
- Electrolyte imbalances
- Medications (statins, prednisone, others...)
How can leg cramps be prevented?
- Stay Hydrated
It is not well known exactly how dehydration and muscle cramping are related, but it is known that dehydration can predispose to leg cramps. Drink at least three full glasses of water each day, including one before bedtime. Also drink plenty of fluid before, during, and after exercise.
- Stretch Regularly
Stretching can relax muscle fibers. When working out, a good post-work out stretching routine can help relax muscles and prevent cramps. Make sure you cool down after exercising, and do not exercise vigorously just prior to sleep.
- Train Gradually
Gradually build up an exercise program, and try to avoid sudden increases in activity. The "10% Rule" is a good rule of thumb: never increase your exercise over one week by more than 10% compared to the week before. Sudden changes in activities can cause leg cramps.
Usually instinct takes over when a leg cramp strikes, and you massage and stretch the sore muscle. This is a perfect instinct and often solves the problem. The best steps are:
- Massage the cramped muscle
- Stretch the muscle (gently!)
- Take a hot shower or bath to warm and relax the muscle
If leg cramps become a persistent and recurring problem, you should be evaluated by your doctor. Because electrolyte imbalances can cause cramping, some blood may be analyzed to ensure the levels of potassium and other electrolytes are normal. There are also muscle relaxing medications that can be prescribed if the muscle cramping is a problem, particularly at night. Finally, your medications and medical history should be reviewed to investigate for possible factors contributing to your leg cramps.