To reduce the risk of dehydration-associated cramps, simply drink more than enough fluids before, during, and after you exercise. On a daily basis, drink enough fluids so you have to urinate every two to four hours. Your urine should be light colored and copious. During extended exercise, drink as much as tolerated, optimally 8 ounces every 15-20 minutes. Lack of calcium.
Calcium plays an essential role in muscle contractions.
Anecdotal stories suggest that athletes who eliminate calcium-rich dairy products can become plagued by muscle cramps. For example, a ballet dancer who added yogurt and skim milk back into her diet reports her cramps disappeared. A mountaineer resolved his muscle cramps by taking calcium-rich Tums. Exercise scientists question the validity of these anecdotes, believing a calcium imbalance is unlikely to be the cause of muscle cramps. After all, the bones are a calcium reservoir and can supply the body what's needed for proper muscle contractions.