Now people pay attention to health and exercise and so on, but sometimes there are accidents, for example, in the exercise of some people will suddenly faint, then this is how it happened? The first thing to think about is not the cause of strenuous exercise, sometimes strenuous exercise will lead to insufficient oxygen supply to the brain, and then there will be fainting, generally this kind of very good treatment, as long as rest for a while on the good, there will be no sequelae, just pay attention to the future not too expensive strenuous exercise on the line. The main consideration is that due to strenuous exercise, a large amount of blood is occupied by the skeletal muscles, the amount of cardiovascular blood is sharply reduced, resulting in insufficient blood supply to the brain. It does not matter, as long as you pay attention to rest on it. When exercising vigorously, the heart rate increases, the muscles and capillaries expand, and blood flow accelerates. If you suddenly stop to rest, muscle contraction stopped, the blood in the muscle can not smoothly flow back to the heart, will cause a decrease in blood pressure, temporary ischemia of the brain, may lead to panic, shortness of breath, dizziness, and even shock. Therefore, built for strenuous exercise, after the exercise to do finishing activities to make the body gradually ease the pressure to avoid the stop and sports syncope. Others may have problems because of the body itself, such as people with anemia or low blood sugar may faint if they exercise a lot, so such people should clarify their physical condition. Others, such as lower blood pressure in the body during strenuous exercise, cerebral ischemia, etc., can cause fainting.