If you have ever awakened from a peaceful sleep with a piercingly painful involuntary muscle cramp in your leg you may have found yourself temporarily, yet agonizingly disabled for as little as ten seconds or as long s several minutes For most people soreness in the affected muscle lingers into the next day.

Although no one knows for sure what causes these nocturnal leg cramps they seem to be associated with overexertion of the muscles, structural disorders in the feet, prolonged sitting or inappropriate leg positions or dehydration.

My personal experience is that most people who work out and complain of muscle cramps can get relief if they add more water to their diet. When you exercise more than forty minutes your body overheats no matter what environment you are in. Add an electric blanket or an overheated room and it is a set up for muscle cramps.

Typical recommendations for water for an exerciser is a half cup for every twenty minutes you are strength training or attempting to enhance cardiovascular endurance. If it doesn't affect your performance you can fill up before you start or replenish after your workout is over.

How much water you need depends on how you live your life. The best way to tell if you're drinking enough is to

• a. pay attention to how often you urinate. If you are taking time out to empty your bladder regularly you're probably getting enough. If your fluid intake is so high that you spend your life looking for the closest rest room you're probably drinking too much.
• b. pay attention to the concentration of color of the urine. People who get enough fluid have unconcentrated urine. People who do not have thick, dark yellow urine.
• c. if you are thirsty your dehydration levels are already approaching dangerous levels.

I recommend people who exercise also add a drink that replaces electrolytes that are lost when you are overheated--whether you sweat or not. It doesn't matter whether you choose one of the drinks specifically designed for this purpose like Gatorade (which can be high in calories) or use a less expensive but equally effective and lower in calorie juice like V-8.

When a nocturnal leg cramp occurs the best remedy is to stifle your scream and straighten the leg as you flex your foot toward your knee. Reach for your toes and pull them toward your knee to stretch the calf. A hot shower, warm bath or massage with ice can also bring relief.

Additionally you can stretch your calves regularly throughout the day or, if it doesn't keep you awake, ride a stationary bicycle for a few minutes before bedtime. Keep blankets loose at the foot of the bed to prevent your toes from pointing downward.

Some healers will encourage you to use quinine sulfate to relieve leg cramps but it can have unpredictable adverse effects and should be used with caution. (In 1995, the US Food and Drug Administration banned the sale of all quinine-based over-the-counter preparations.)

Since not all cramps are associated with physical activity you should check with a doctor if cramps persist, or are often present in other muscles despite hydration, muscle work and stretching routines. It's not likely that you have a condition that interferes with muscle metabolism or affects circulation but it is better to be safe than sorry.