In the Yellow Emperor's Internal Classic, Shunqi is a four-time chapter in one day, it points out that "when people become popular and sick, they become wise once they become ill." In the sentence, "Dan" is equivalent to "Yinshi". Yinshi is booming in Qi and blood due to the "Lung Meridian". At this time, practicing Gong is precisely in order to make the meridians and collaterals of human body conform to the resonance law of cosmic electromagnetic waves and better absorb energy from the universe. I do not know for thousands of years, a large number of Wushu practitioners, Qigong practitioners, health preservers and other practices have proved that "Yinshi" is the golden time for practicing Kung, can better help growth and increase strength.

Why emphasize Yinshi's practice? In the great scientific classic Huangdi Neijing, it has long been argued that the practice of Qigong facing south in Yinshi is more effective. We know that the human body's Qi and blood run in a day and night, the rise and fall of the strong and weak open and close cycle, and the operation of the cosmic celestial bodies is closely related. The "meridian flow injection" of traditional Chinese medicine tells us a truly scientific "biological clock" phenomenon.

In a day and night, the best time to practice is Yinshi. The ancients had twelve hours in a day and night. Each hour lasted for two hours. Yinshi corresponded to 3-5 a.m.