It is usually recommended that running is the best time period for exercise at 19-20 pm. Because this time running has the following three benefits, 1, the oxygen density in the air is relatively high, at this time the plant does not photosynthesis, so will not discharge too much carbon dioxide, so the oxygen content in the air is relatively high, 2, 19-20 pm, is the human body’s recent basal metabolic rate is relatively slow, at this time after exercise will improve the body’s basal metabolic rate, thus playing weight loss and fat loss with half the effort. 3, between 19-20 pm, such as relaxation after exercise, will stimulate the cerebral cortex cells. And then after 2 hours of full rest, so that the blood circulation is more rapid, will improve sleep, improve the quality of sleep.