Stomach, intestine, liver, gallbladder and other internal organs are not suspended, but wrapped in some films, and finally tied to the spine like a belt, so that people will not disturb them when rolling. \ x0d \ But when running, when the steps fall together and the body shakes, these organs will shake and move, which will inevitably affect the membrane wrapped on it and the belt tied to it. When the membrane and band are stimulated, the stomach hurts. Especially for people who usually lack exercise, the muscles in their stomachs are very loose and they don't have much strength. When they run, their internal organs shake badly and their stomachs will hurt more easily. \ x0d \ People who often take part in physical exercise have strong abdominal muscles and seldom have stomachache. \ x0d \ As we all know, there is a diaphragm between the chest and abdomen. Here are the liver, spleen, stomach, intestines and other viscera. When breathing, the diaphragm should move up and down to push the viscera. When breathing with the mouth open, the air intake is large and the pressure under the diaphragm is heavy, which will greatly promote the viscera. The internal organs are shaking because of the influence of running. If you push so hard, the diaphragm will be pushed down even further. In this way, every time you take a breath, the diaphragm will be pressed down and you will gasp when running. Internal organs are strongly affected, and the stomach will naturally hurt more. \ x0d \ Therefore, running posture is very important. When the toes touch the ground, they are elastic, the visceral vibration is small, and the stomach is not easy to be injured; Poor heel elasticity, great visceral vibration, and easy stomach pain.