Because the body's oxygen consumption can be accelerated during exercise, in order to get more nutrients and oxygen to meet the acceleration of the body's metabolism, the heart must speed up the pulse to accelerate blood circulation, because oxygen and nutrients are in the blood. Therefore, it is normal for the pulse to accelerate during exercise, but it is normal within a certain range. The pulse or heart rate of a normal person is between 60- 120. Generally speaking, under static conditions, after 60-85 times of exercise, the pulse or heart rate of adults will not rise more than 120. If it exceeds 120, it will be abnormal to have an ECG check!
There are also some athletes with good physical fitness whose heart rate is lower than 60 at rest, which is normal. That's because these athletes have good physical fitness, higher than normal cardiac output and higher than normal hemoglobin oxygen content. If an ordinary person's static heart rate is lower than 60, it may be bradycardia and should go to the hospital for examination!