We all experience the common cramp (a charley horse) when out of the blue a muscle contracts violently and will not let go -- until it is good and ready. Most people have experienced a cramp. It usually comes as a surprise, and can drop even the strongest athlete to their knees. Cramps can happen during or after exercise, up to six hours later and during sleep (called night cramps). The cramp can last seconds or up to 10 minutes and the muscle can be sore up to 24 hours later.

What causes cramps? Who knows! It seems to be a medical mystery. More importantly, what can you do about them? Everyone seems to have an answer

• Take potassium, zinc, and magnesium
  
• Drink plenty of water
  
• Stretch before and after exercise
  
• Turn your toes toward your head and massaging it out.

One theory that seems reasonable to me is that we need more fluid -- simple dehydration. We also really need sodium and potassium. When we sweat too much, the fluid that bathes the connection between the muscle and nerve is depleted of sodium and potassium, which are lost through sweat, so the nerve becomes hypersensitive.

Preteens and teens who are growing a lot seem to get more cramps, which is not really explained by any of the common explanations. Cramps are not worrisome unless they happen frequently. If they happen at night, try stretching your legs before bed, particularly the calf muscles. Keep your blankets loose around your feet, and don't sleep with your knees bent and your toes pointed down, which shortens the calf muscles.

There are medical reasons cramps occur, particularly in adults. So they should not be brushed off, especially if they are recurring. Narrowed blood vessels, usually from atherosclerosis (hardening of the arteries), compression of a nerve, possibly from spinal stenosis, hypothyroidism, and potassium deficiency can cause cramps, as can medications like diuretics used to lower blood pressure.