Leg cramps are often related to problems with sodium, potassium, calcium and magnesium balance, as well as to problems with deficient hydration. So, making sure that you drink enough fluids (including juices, "sports drinks" and fluids that contain minerals and glucose in addition to water) is important. Some people find that adding a little bit of salt to the diet (such as salting your food on a regular basis) helps. For some people, taking a small amount of supplemental magnesium (tablets are available at drug stores and/or health food stores) daily, or calcium (Tums, 2 tablets chewed and swallowed two or three times daily is a reasonable dose) is helpful.

Cramps also occur when unaccustomed exercise occurs at intensity levels that are too high. So, a good warm-up, and gradual increments in intensity of exercise will go a long way toward reducing cramping.

When a cramp actually occurs, gently stretching the involved muscle will usually cause it to subside, and at that point, the exercise session should be terminated for the day.

If the above suggestions don't help, you need to have your specific situation evaluated by a knowledgeable physician.