A leg spasm, often referred to as a charley horse or leg cramp, is the result of a sudden, often painful, contraction of the muscles. Many athletes, particularly runners, have experienced this phenomenon. While the exact cause of leg spasms is unknown, taking certain preventative measures before and during your run may prevent them from occurring. If your legs continue to spasm after running, even though you are taking proper preventative measures, consult a doctor.
Although experts have been unable to find the exact cause, several factors have been identified as contributing to muscle spasms after running. Dehydration and muscle fatigue are the most common factors cited. Having low levels of electrolytes, including potassium, calcium, sodium and magnesium, affects the way muscles contract and may lead to spasms after your run. In some cases, the nerve that controls the muscles in your legs gets irritated, leading to pain and spasm.
Spasms caused by fatigue may be prevented by stretching your leg muscles to increase flexibility. Warm up your muscles before you stretch to avoid straining them while stretching. A warmup can include several minutes of jogging in place or calisthenics. Pace yourself and avoid running to the point that you feel drained or your muscles get sore. To avoid low electrolytes and dehydration, start hydrating the day before you run and drink 1 to 3 cups of water right beforehand. If you are going on long run, take small sips of water during your run. Drink water or a sports drink enhanced with electrolytes after exercising, especially if you have been sweating a lot. Avoid running in the heat to prevent excessive sweating, which can lead to dehydration and lowered electrolytes.
When you feel a spasm coming on after you run, stop any activity you are doing and stretch and massage your legs until it goes away. If your muscle is stiff, applying heat can help relax it and reduce the spasm. Sore muscles, however, will benefit more from applying an ice-pack or a bag of frozen vegetables. Wrap a towel around the ice-pack to avoid damaging your skin. Taking an over-the-counter non-steroidal anti-inflammatory medication, such as ibuprofen, may help relieve any soreness. Drink an electrolyte-enhanced beverage to help with dehydration.
Muscle spasms in the leg that don't go away with self-care measurements can indicate a more serious problem. If the spasm isn't diminished after an hour -- or if it is extremely painful -- seek immediate medical attention. Leg spasms that occur repeatedly after you run, in spite of taking preventative measures, might indicate an underlying medical disorder, such as mineral deficiency or nerve disorder. Consult a doctor if this is the case.