Great information with a funny bent taken through an interesting translation. Happy winter solstice to you all. 
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Life Cultivation in Winter
Winter refers to the period from the Beginning of Winter to the previous day of the Beginning of Spring which includes the solar terms of Slight Snow, Great Snow, the Winter Solstice, Slight Cold and Great Cold chronologically according to the Chinese lunar calendar. Winter, the coldest season in a year, is a season of excessive yin qi and the hiding of everything. At this time, yin qi is in excess while yang qi conceals. It is a world of ice and snow everywhere. All things hide the vitality. The grass and trees are withered, fallen, and scattered about. The insects hibernate. The yang qi of the human body also stays inside accordingly. The human metabolic function is in a relatively slow state. Health preservation in winter should conform to the features of concealment of yang qi and hibernation to avoid cold and approach heat, preserve yang and yin. This is in agreement with “the principle of nourishment and hiding.”

Regulating the daily life
In winter, going to bed early is advisable to nourish the human yang qi while getting up late is suitable for protecting yin and essence. This is because retiring to bed early and rising late can help yang qi descend and conceal, yin and essence accumulate so as to maintain the balance of yin and yang of the human body. Do not work until the sun rises; avoid cold and approach heat to prevent external cold from impairing yang. In addition, adopt the heating devices to maintain a proper room temperature Very low room temperature may impair human yang qi and make people subject to common cold; very high room temperature makes the skin striae open and yang qi unable to conceal, and pathogenic cold can easily invade the body, giving rise to affectation by exopathogen and other diseases. 

In terms of clothing, wear more or less clothes constantly as the weather changes. The cotton fabrics are the best for tailoring the underwear because they are soft, comfortable, and good in heat preservation; the outer clothing should be slightly larger. Excessively thin clothing may easily impair yang, make people susceptible to common cold or numbness and pain of the waist and legs; excessively thick clothing may stir yang qi to affect its concealment. The shoes and socks should be a little larger so as to keep qi flow free and harmonious, limbs comfortable and warm. The hands and feet are liable to chilblain, so particularly in need of heat preservation. 

Regulating emotions
Winter corresponds to the kidney internally. The kidney controls the storage of essence and is the congenital base of life and emotionally associated with fear and fright. Excessive or sudden fear and fright may impair the kidney and cause the pathological changes of the kidney. Accordingly, in winter, the time of hiding, people should stabilize emotions and cultivate the mind. They should be emotionally implicit, quiet, and happy to avoid excessive emotional activities; fear, fright, and dysphoria should be avoided most so as to guarantee that the normal physiological feature of the hiding of yang qi is not interfered with. Only when the mind is tranquilized can yang qi inside the body be hidden, yin and essence accumulated. This can create the conditions to generate and develop spring yang for the coming year. 

Regulating the diet
Ingestion of tonics in winter has been the traditional life cultivation method in China for several thousands of years. Modern researchers believe winter is the season in which nutrients are most easily accumulated during the year. Therefore, nutrients can be transformed into energy to the greatest extent and stored inside the body by means of recuperation with the proper diet to nourish viscera, limbs, and bones. Ingestion of tonics in winter includes the two types of tonification with the diet and tonification with drugs. Tonic foods include mutton, chicken, beef, and so on; tonic drugs include ginseng and other blood and yin tonics. Foods and herbal supplementation should address personal deficiencies so that the constitution is supported and not overburdened. Patients should consult with their doctors to determine the proper direction of supplementation in winter they should take. 

Physical training
Though it is cold in winter, people should still persevere in their physical training. This is the basic method to strengthen health. The sports events should be flexibly selected in accordance with the individual’s and local conditions in the physical training in winter. The events suitable for indoor physical training in winter include health-strengthening massage, keep-fit qi gong, taijiquan, settling-up dance, and so on. The outdoor training events include long distance running, heel-toe walking race, gymnastics, ball games, ice skating, and skiing, etc. The climate in winter is severely cold. All the living things in the universe are in the state of hiding. People should pay attention to prevention of cold and heat preservation to make yin and essence hide inside, yang qi not release excessively. This is an agreement with the natural climate in winter. Only in this way can “yin be even and well and yang firm,” diseases eliminated, and life prolonged. It is best to select the movements with large amounts of exercise  and to make the body sweat slightly when the sun rises. It is not advisable to rise early so as to avoid stirring up yang qi of the body. Meanwhile, avoid the training in strong wind, bitter cold, heavy snow, fog and dew. This can not only reach the purpose of avoiding cold and warming the body, but also maintain a cheerful frame of mind to gather essence, qi, and vitality inside. This is in agreement with the principle of “preserving health by hiding” in winter. Violating this principle may incur the impairment of the kidney qi and flaccidity with cold limbs when spring comes to result in the weakening of the body’s adaptation to the spring sprouting. 

It should be emphasized that temperature inversion often exists in the morning due to the influence of cold high pressure. Namely, the temperature of the upper atmospheric layer is high while temperature of the terrestrial surface atmospheric layer is low, with weakened convective activities. Consequently, the chemical atmospheric pollutants from factories, cars, domestic kitchen ranges, etc. cannot easily diffuse into the upper atmospheric layer. As a result, these pollutants accumulate and stay in the breathing belt of the lower atmospheric layer. At this time, the people having the outdoor physical training exactly become the victims. Accordingly, it is not suitable to have the outdoor physical training in the early morning, especially for some old people, viewed from the angle of atmospheric pollution. 

— Taken from Life Cultivation and Rehabilitation of Traditional Chinese Medicine, Nanjing and Shanghai Universities of TCM, 2003.