A healthy person can't sleep far, because the function of keeping fit is to prevent diseases that he has never suffered. Ge Hong said in Bao Puzi's Extreme Words: The prescription of health preservation is: you can't spit far, you can't act fast, you can't listen hard, you can't watch for a long time, you can't sit for a long time, and you can't be tired. ..... I don't want to work hard, get up late, sweat, sleep more, run around and overlook. The function of exercising to maintain health is to prevent diseases that have not happened, to ventilate the qi that is out of harmony, to exercise to make the official qi unobstructed, and to close the three palaces to coagulate blood. It is really a great method of maintaining health and a metaphysical technique of removing diseases. The principle of keeping fit is easy and healthy. One or more methods can be practiced selectively on the premise of not hurting or hurting. Taoist health care emphasizes that the amount and intensity of exercise should be appropriate and should be measured by oneself.