Cramps in the calves during exercise arise for the following reasons: 1. Insufficient warm-up: the patient is not adequately prepared before exercise, the muscle temperature is low, at this time the sudden movement will cause continuous tonic contraction of the muscles, resulting in cramping symptoms. If the patient is fully warmed up before exercise, so that the muscle temperature rises, the viscosity between the muscles is reduced, it is not easy to appear the clinical symptoms of calf cramps. 2, excessive exercise: in the process of exercise, if excessive exercise is also easy to make the calf cramps, need to control the amount of exercise to prevent calf cramps, at the same time after exercise to stretch the calf muscles, to relax the calf muscles, can also prevent cramps. The occurrence of cramps can also be prevented by stretching the calf muscles after exercise. Therefore, most of the calf cramps that occur during exercise are caused by the above-mentioned reasons, and through active prevention, the symptoms of calf cramps can disappear.