Exercise-induced muscle cramps are common among cyclists at the end of demanding races. Some riders seem to have more frequent episodes of muscle cramps than others, but most cyclists have experienced the phenomena. Your performance will be lowered if you have leg cramps, so there is good reason to learn how to avoid such.
Hydration with water and different electrolytes may protect riders from muscle cramps since dehydration and electrolyte imbalance are closely related to these involuntary, painful muscle contractions.
One of the potential risks is exercising in a hot environment because of dehydration and massive loss of sodium, potassium, magnesium, and other electrolytes.
When water loss is recovered with plain water, there will be a net loss of electrolytes. In the old days hard-working people who worked in mines died because of an excessive water intake that diluted the concentration of electrolytes. This was called ‘Miner’s Cramp‘.
Carbohydrates, sodium and water does not protect you from muscle cramps
Scientists from the University of North Carolina have published an article in Journal of athletic training, June 2005: Influence of Hydration and Electrolyte Supplementation on Incidence and Time to Onset of Exercise-Associated Muscle Cramps.
In this study, 13 men with a history of exercise-induced muscle cramps performed two tests designed to provoke muscle cramps in the calves. One test was done with water, carbohydrates, and sodium supplementation, while the other test was done without any supplementation. The findings were that nine people developed muscle cramps in the hydration/supplementation trial, and seven people did in the dehydration trial.
But carbohydrates, sodium and water may prolong the onset of cramps.
These findings do not indicate that hydration and supplementation with carbohydrates and electrolytes protect against muscle cramps. Instead, it tells us that there are other factors implicated in the development of exercise-induced muscle cramps. However, in the hydration/supplementation trial, the time to onset of muscle cramps was prolonged (36.8 minutes completed before onset, compared to only 14.6 minutes in the dehydration trial.)
In my opinion, the study should have included a trial with plain water only. This should be done to see if the water or the supplementation prolonged the time to the onset of muscle cramps.
