Modern people, represented by the analysis of Confucian classics in Huangdi Neijing, think that nourishing yang in spring and summer and nourishing yin in autumn and winter can be summarized into three meanings: first, adapting to the four-season regimen, growth belongs to yang, and collection belongs to yin, so the gas for long-term health preservation in spring and summer is nourishing yang, and the gas for collection in autumn and winter is nourishing yin; Second, nourishing yang refers to nourishing the heart, liver and yang; Nourishing yin refers to nourishing lung, kidney and two yin; Third, to raise yang should obey the growth characteristics of yang, so that it can be vented; And nourishing yin should obey the characteristics of Yin Qi's collection, and don't let Yin Qi vent. The above explanation explains the theoretical significance of "nourishing yang in spring and summer and nourishing yin in autumn and winter" from different angles. No matter which point of view is to illustrate that the principles and methods of health preservation in different seasons are different. Only when people understand the meaning of "nourishing yang in spring and summer, nourishing yin in autumn and winter" from a theoretical height can they better "be suitable for cold and summer in all seasons". Specific to the four seasons of spring, summer, autumn and winter, how do people raise yang and yin? There is a more detailed discussion in "A Brief Discussion on Four Qi Regulating Spirit in Neijing", which is now extracted as follows: "Spring and March are called the birth of Chen, the birth of heaven and earth, and all things are glorious. Lying at night and getting up early, striding in court, being slowed down, so that life, living without killing, giving without taking, rewarding without punishment, this spring should be the way to keep fit. On the contrary, it hurts the liver, and it is cold in summer and has few elders. " This is the way to keep in good health in spring, that is, the way to raise yang in spring. It means that in spring, in the first, second and third months, the yang rises, everything sprouts, and nature presents a vibrant face. Heaven and earth breed the spirit of hair growth, and everything is thriving; People should go to bed late and get up early, stride in the courtyard, let their hair loose, relax their bodies and make their minds full of energy. Treat things, don't kill them when you are alive, don't deprive them if you give them, and don't punish them if you reward them. This is the reason to adapt to spring and regulate the "internal heat" of the human body. If the human body violates this truth, it will hurt the liver qi. Liver qi is injured in spring, and cold diseases will occur in summer. This is because people's physique is not strong enough to nourish "Qi" in spring and "Long-term Qi" in summer. According to the original text, raising yang in spring is mainly reflected in: "going to bed late and getting up early": because there are more yang and less yin in spring; "striding in court": because "exercise leads to yang"; "Make ambition alive": make ambition and meaning full of germinal qi, so as to adapt to the germinal qi between heaven and earth; "It turns cold in summer": the cold syndrome in summer is the result of the failure of yang in spring.