Running heart rate above 200 beats/min is relatively dangerous, its already reached or close to the limit heart rate that human can count, i.e. for a normal person, the highest heart rate reached during exercise. The limit heart rate for normal people is 220 minus their own age, for example the limit heart rate for a 30 year old is 220-30 which is 190 beats per minute. Currently the world statistics can reach the highest limit heart rate is 210 beats per minute. Therefore an average adult male exercising with a heart rate of 200 beats per minute can easily cause tissue hypoxia, and once there is heart failure, the patient has a poor prognosis and may have various complications, even leading to death, and needs to immediately reduce the amount of exercise. Whether it is anaerobic exercise, or aerobic exercise, it is necessary to follow the appropriate heart rate to achieve the best exercise effect, so maintaining the optimal exercise heart rate is important for exercise safety and exercise effect.