Pain in the chest after walking fast may be caused by a fork in the air, mainly due to the spasm of the diaphragm, resulting in pain in the chest. After walking for a long time and strenuous walking, the skeletal muscles and the muscles of the limbs will consume a lot of nutrients and blood from the body, which will lead to transient ischemia and lack of oxygen in the muscles inside the abdominal cavity, including the respiratory muscles, resulting in spasms, which will manifest as pain. Rest should be taken immediately, try to use abdominal breathing to reduce the pain, or massage the chest area with your hands, or gently tap the chest area to relieve the pain. It is also possible that the patient has a gastric disease, such as chronic gastritis or gastric ulcer, which may trigger pain after walking for a long time, and the pain is very obvious in the chest and upper abdomen. If necessary, gastroscopy can be performed to clarify the diagnosis, gastroscopy can be found in the gastric mucosa with chronic inflammation, or ulcerative changes, the need for medical treatment can be.