The cramp or muscle spasm is an involuntary, brief and painful. The causes that trigger a cramp may be multifunctional: fatigue, metabolic visual impact disorders, dehydration, nerve or vascular alterations. Although in the case of sports physiologists do not quite agree on what is the cause. 's cramp that occurs in athletes is usually by electrolyte disturbances,
so that the fluid lost by sweating and not replace it there is a decrease of ions involved in intramuscular contraction process (magnesium, potassium, calcium),
giving a failure in the transmission of nerve impulses, preventing the muscle relaxes and suffering cramp. The best means of prevention is a good hydration and nutrition before and during exercise, and whether the practice will be long-lasting hydration with isotonic drinks to replenish electrolytes.
Once produced the best cramp is to stretch the muscle gently and gradually. The application of heat can also help, as it will produce distillation and provide more nutrients and electrolytes to the muscle. Source: World of Vito for runners