Stay healthy. According to the query of China Literature Network, "keeping in good health in winter solstice" refers to taking a series of measures to recuperate the body during the solar term from winter solstice, following the laws of nature and life process. "Tropical Year Method" is a word with strong characteristics of China traditional culture, which describes the cycle of time flow and natural laws. "Keeping in good health from the winter solstice" means that the yang in nature begins to rise gradually and the daytime becomes longer.