In general, yawning when exercising is usually caused by lack of oxygen to the brain. Since a large amount of blood will flow to the limbs and trunk when the patient exercises, giving priority to supplying oxygen to these parts and making the brain relatively short of oxygen, and at the same time, brain cells are extremely sensitive to lack of oxygen, which can make the patient yawn due to lack of oxygen to the brain. In addition, yawning can, to a certain extent, promote the body’s deep breathing exercise, expel more carbon dioxide, and thus improve brain activity. Therefore, there is no need to be overly concerned about this condition. By adjusting the amount of exercise, the way of exercise, preparing for exercise, and exercising under good physical function and in a suitable environment, the symptoms of yawning upon exercise can be effectively relieved. However, it should be noted that some diseases can also cause patients to yawn when exercising, such as pulmonary insufficiency, chronic pulmonary heart disease and other lung diseases, when patients exercise can make their arterial oxygen saturation drop, carbon dioxide partial pressure is too high, oxygen partial pressure is too low, etc., resulting in brain hypoxia and thus cause this symptom; patients with cardiovascular diseases, such as coronary heart disease, cerebral atherosclerosis, etc., in addition to yawning when exercising, can also be accompanied by peripheral Patients with cardiovascular diseases, such as coronary heart disease and cerebral atherosclerosis, in addition to yawning upon exercise, may also suffer from weakness, chest tightness, shortness of breath, nausea and vomiting. Therefore, such patients should pay attention to the frequency and intensity of exercise to avoid adverse consequences when exercising.