Running calf pain may be caused by the following reasons: 1. It may be caused by excessive fatigue. If the patient does not exercise before, sudden activity may lead to excessive fatigue of the muscles, producing a large amount of lactic acid deposition in its internal, and then cause soreness here. 2, may be due to cold caused by. Many patients are used to wearing very little clothes when running, resulting in frequent cold in the calf area, which may produce muscle spasm here and then cause soreness. 3, may be caused by injury to the calf area, often seen in patients do not do a good job of warm-up activities or do too intense running activities, resulting in some muscles and tendons in the calf area strain, and then cause pain. 4, may be The pain is often caused by osteochondritis, which is more common in adolescents during the growth period. This type of patients due to rapid growth and development, and more activities, often easy to cause the calf part of the periosteal inflammation. Once this condition arises, it often manifests itself as pain in the front inner part of the calf, the bone surface of the tibia, and the pain increases significantly when the patient runs long distances.