A cramp occurs when the nerves tell the muscle to tighten as a defensive measure to keep it from stretching too rapidly. Exercise physiologists have two theories on why cramps occur:

1. Fatigue of nerves. As nerves fatigue during prolonged exercise they become more excitable, and more likely to overreact to prevent a muscle from stretching too quickly.
2. Sodium losses. Sodium losses from sweating or not consuming enough sodium during exercise also make the nerves more excitable.

One or both may operate if a cramp grabs you.

To prevent cramps:

• Get enough potassium, calcium and magnesium in your daily diet.
• Stretch regularly throughout the week and at rest stops.
• Increase fitness so that fatigue is less of a factor.
• Warm up before and cool down after hard rides.
• Pace yourself during a ride so that cumulative fatigue is less of a factor.
• Drink enough fluid to satisfy your thirst, but don’t overdrink, which risks hyponatremia (low blood sodium).
• Consume sodium during hot rides of more than several hours. The American College of Sports Medicine recommends 500 - 700 mg of sodium per liter of fluid (1.06 quart). Sports drinks don’t have this much. Tomato and V-8 juice, dill pickles, deli turkey and salty pretzels are all good sources as are plain salt tabs from the pharmacist.
• Vary your position on the bike, stand and sit, coast and stretch your calves and hamstrings.

To treat cramps:

• Break the cramp by gently stretching the affected muscle.
• Flush the cramp by pedaling with the affected muscle working slightly and otherwise just going along for the ride

For more get the 10 page eArticle Preventing & Treating Cramps for just $4.99 from RoadBikeRider.com.

Stretches illustrated