Chest fork pain is caused by spasm of respiratory muscles, commonly the spasm of diaphragm. When the body is in strenuous activity, because it has not been effectively warmed up before, that is, not all the muscles of the body are mobilized, sudden strenuous activity will cause the muscles inside the abdominal cavity, such as the muscles of the stomach or small intestine, respiratory muscles of the muscles of transient ischemia and hypoxia, so it will lead to muscle spasm, chest pain and possibly bilateral pain in the rib arch. When the pain is most pronounced, it can usually be improved by resting for a period of time. You can also try abdominal breathing, or massage or pat the most pronounced area of pain with your hands to help relieve the respiratory muscle spasm.