What does March 9th mean in winter?

"Sanjiu" refers to the third nine days from winter to the future, which is about the middle and late period of 1. This is the coldest time in winter.

The coldest reason of "March 9th":

Judging from the heat absorbed and emitted by the ground at that time, although the days are short and the ground absorbs the least solar radiation heat in winter, the heat emitted by the ground at this time is more than the heat absorbed, and the temperature near the ground will continue to be low. When the solar heat absorbed by the ground is almost equal to the heat emitted by the ground, the temperature will reach the coldest.

After the Third Nine-Year Plan, the heat absorbed by the ground will be more than the heat lost by the ground, and the temperature near the ground will gradually increase. Therefore, the coldest time of the year generally appears from winter to around March 9.

Winter development information and exercises 39

Pay attention to health care, and more exercise is an important way to health care.

In the cold winter, practicing martial arts can not only enhance physical fitness, but also exercise people's strong will not to be afraid of cold. Enhance the body's adaptability to cold. As the whole body is active, breathing is deepened, digestion is enhanced, metabolism is vigorous, physical condition is improved, and health level and sports performance will be improved accordingly.

Baidu Encyclopedia-Midwinter