Qigong practice is based on the yinyang theory of Chinese medicine. The yinyang theory is very important for qigong practice. Exhalation is excretion, and inhalation is nourishing. For instance, those with hyperactive yang and excess of fire should emphasize on exhalation during qigong training, to clear away the excessive fire. On the other hand, those with deficiency of yang and qi-collapse should enhance inhalation, to benefit the insufficient yang.
During the four seasons of a year, there are climatic changes. These are “spring warm, summer heat, autumn cool, and winter cold”. The qigong training should be varied in accordance with such seasonal changes of yin and yang. As it was said in the earliest Chinese medicine classic Yellow Emperor's Internal Classic, “the saint nourishes yang in spring and summer, and nourishes yin in autumn and winter.”
Qigong was developed based on the theory of channels (or meridians) and collaterals, while the development of qigong itself provides evidences for the existence of channels and collaterals. Qigong practice has enabled better understanding of conjunctions and interrelations among various channels.
In qigong practice, methods such as Heavenly Circuit of Qi can help improve qi to flow and circulate normally inside channels and collaterals. The exercise of The Small Heavenly Circuit of Qi can help improve the smooth circulation of qi through the Ren (or Conception Vessel) and Du (or Governor Vessel) Channels. The practice of The Large Heavenly Circuit of Qi can help improve the smooth circulation of qi in the twelve major channels and the eight extra channels.
Qigong practice can also improve the health of internal organs. It helps adjust yin and yang in different organs, and improve the blood and qi circulation in these organs. These are the basis for maintaining health.
