What do you mean by "three-nine in winter training and three days in summer training"?

The proverb "practice for three days in winter and three days in summer" is the experience summed up by predecessors in the long-term exercise process and has certain scientific truth. But for the elderly, it is not appropriate to practice dog days in summer.

As we all know, the dog days are the hottest season in a year, and its climate is characterized by high temperature, low pressure, high humidity and low wind speed. This climatic condition has obvious adverse effects on human health. The organ function of the elderly declines, and the water content in the body is about 15% less than that of the young people, so the heat resistance is far lower than that of the young people.

"Practice three or nine in winter and three volts in summer." It means that no matter how cold and hot the weather is, we should persist in physical exercise, so that our body can better acquire the ability to keep pace with the four seasons and adapt to the cold and heat. In fact, in the hot summer, people who don't like physical exercise, the more afraid of heat, the more hot they feel, the less active they are, and the worse their adaptability to the external environment. Exercising in a hot environment can dilate subcutaneous capillaries, accelerate the opening of body glands, improve heat dissipation ability, and make the body have a stronger ability to regulate body temperature, so many experts advocate "summer training in dog days".