If you haven't done similar exercise before, it's basically excessive exercise, and your cardiopulmonary function can't keep up. In other words, the blood is mostly concentrated in the limbs and lungs, and the human body consumes a lot of energy and energy to replenish oxygen to the body, so it causes gastrointestinal ischemia, and the vagus nerve in the stomach will send a signal that "it is not suitable to eat at this time". In addition, due to excessive exercise, the short-term body temperature may rise too fast, which will inactivate some enzymes in the body, so it will cause short-term stomach discomfort. Generally speaking, the problem is not big. Drink some warm water and rest 10 minutes.

But if you have adapted to the intensity of exercise and this happens suddenly, you should consider whether you have gastric ulcer or chronic gastritis, gastroptosis and other stomach diseases.