Leg cramps are caused by muscle or tendon spasms, and the most common cause of cramps in growing adolescents is calcium deficiency. Adolescents grow faster and are prone to a relative lack of calcium, leading to muscle or tendon spasms and cramps. Young adults in the growth and development period should pay attention to calcium supplements, you can take oral calcium tablets, eat more food with high calcium content, such as milk, pork bone soup can drink more. Boys leg cramps, usually appropriate more sunshine, more exercise helps to reduce the calcium-induced convulsions. Pay attention to protection from cold and warmth, the stimulation of cold can induce cramps. A very important factor for leg cramps in boys is too much activity, too intense, and not well prepared for exercise. So if a boy develops leg cramps, look for similar possibilities and prepare your movements before exercise, while avoiding sports injuries.