Chinese medicine generally believe that running in the morning is good. According to the theory of Chinese medicine yin and yang growth, the morning Yang Qi rise, Yang Qi in the day, with the growth of Yang Qi and Yin Qi abatement, the body’s physiological functions from inhibition to excitement, that is, “yin long yang elimination” process, so it is suitable for running in the morning, in line with the laws of nature. Noon a yin born, mid-day to dusk, the yin gas gradually, to the midnight yin gas, yang gas and then gradually reduced, the body’s physiological function from excitement to inhibit, that is, “yin long yang elimination” process, so it is not suitable for night running. Morning or night running needs to be combined with their own actual situation, there is no absolute saying, but also can be combined with their own physique to choose the right time to run.