“冬练三九,夏练三伏”,这是前人练功健身的经验,有一定的科学道理。例如,在严寒天气下锻炼,能增加机体对寒邪的抵抗力,可预防冬季常见病的发生;而在酷热天气下锻炼,能提高人的耐热能力,使得机体能更好地适应炎热的气候,从而达到防病健体的目的。但对老年人来说,“夏练三伏”就 “Winter training thirty-nine, summer training three volts,” This is the experience of the previous practice of fitness, there is a certain scientific truth. For example, exercise in cold weather can increase the body’s resistance to cold pathogen, can prevent the occurrence of common diseases in winter; while training in hot weather can improve people’s heat tolerance, making the body can better adapt to the hot Climate, so as to achieve the purpose of disease prevention and health. But for the elderly, “summer exercise three volts” on it