Life Reserves and Yang Energy Preservation: Theories of Kidney Qi and Yuan Qi, Principles of Quiet Health Preservation, and Details of Body Fluid Balance

Men should pay special attention to nourishing their kidneys, as vital energy (yuanqi) is stored in the kidneys. Vital energy is the innate essence, like a "gas cylinder" for life; its depletion rate determines lifespan. Symptoms of Yang deficiency include cold limbs, frequent urination at night, and decreased sexual function. Treatment should focus on warming and tonifying kidney Yang, and include regularly consuming mutton and dog meat. Daily care should include keeping joints, waist, and abdomen warm; minimizing air conditioning use in summer; and ensuring sleep before midnight. Moxibustion can be applied to four acupoints: Shenque (CV8), Qihai (CV6), Guanyuan (CV4), and Zhongji (CV3), each time until the skin becomes warm and red.

Energy conservation and nourishing Yang energy are key to longevity. 1. Quiet Health: Calm the mind to reduce metabolism and minimize Yang energy depletion. 2. Low Temperature Health: In winter, room temperature should not be too high; connect with the earth's Yin energy and eat more aquatic foods (rice) and winter-hardy foods (winter wheat, cabbage). The three essential elements for life reserves are diet, sleep, and sexual activity. For sleep, naps at midnight and noon are recommended; for sexual activity, the focus should be on Yin-Yang balance.

It's crucial to correct common misconceptions about exercise. Sweat is considered the fluid of the heart; excessive sweating depletes body fluids and damages Yang energy. Ancient practitioners advocated for "sweating until a light layer of sweat" during exercise. The amount of sweat produced is influenced by body type, body fat percentage (overweight individuals tend to have less body fluid), and water intake. Excessive sweating does not equate to better results; exercises that don't induce sweating, such as walking, are equally beneficial.

Staying up late is the primary cause of Yang deficiency. Activities after 11 PM greatly deplete the body's stored Yang energy, leading to a sallow complexion, depletion of Qi and blood, and increased susceptibility to cold invasion. Furthermore, endless desires are also a major cause of Yang deficiency; selfishness, jealousy, and greed should be avoided. Qi circulation exercises can help gather vital energy: First, exhale and focus on the solar plexus; second, guide the warm current towards the dantian; third, focus on the dantian to form a Qi ball; fourth, open the Du meridian.

Body fluids are the guardians of health. Within the vessels, they manifest as blood; outside, they appear as sweat, urine, and saliva. High fever or severe vomiting can deplete body fluids, leading to damage to both qi and blood. Zhang Zhongjing proposed "preserving stomach qi and retaining body fluids," and traditional health preservation methods, such as "rinsing the mouth and swallowing saliva," can promote a radiant complexion. In summer, when sweating is profuse, one should eat sour foods such as hawthorn and dried plums to generate fluids and reduce sweating; in autumn, lilies and sesame seeds are suitable for nourishing yin and moistening the lungs; in winter, one should protect yin essence and minimize the loss of body fluids. Eating porridge in the morning is an excellent way to generate body fluids, benefit the diaphragm, and nourish the stomach.