0 1 early morning, all kinds of physiological functions of human body are in a low stage. Having a rest all night is not suitable for physical exercise. The organs of the human body are in a relatively balanced state. In early winter, human blood viscosity is high, and hormone levels in the body are high. In the cold morning, physical exercise easily affects vasoconstriction, increases blood resistance, and leads to hypertension and cardiovascular and cerebrovascular diseases. In addition, the coordination of the whole body is poor, the outdoor light is weak in the early morning in winter, sometimes the snowy road is slippery, and the body reacts slowly in an emergency, which may easily lead to accidents such as falls and fractures.
The outdoor environment in the early morning in winter is not suitable for physical exercise. In early winter, the outdoor temperature is mostly below zero degrees Celsius. Five o'clock in the morning is the "morning cold period" (one of the coldest periods in winter morning). The temperature is the lowest, and the indoor temperature is often above 10 degrees Celsius (there is indoor heating in northern cities, and the indoor temperature will be higher). In this way, when the human body shifts from warm indoor exercise to cold outdoor morning exercise, it is easy to catch a cold and respiratory diseases. In addition, because there is no sunshine at night, plants only breathe oxygen and carbon, so the oxygen content in the air is the lowest before sunrise, while the carbon dioxide content is higher. In addition, in the early morning of winter, the air quality is poor and the air pressure is low. Inhalable particles and dust in the air are usually suspended within two meters from the ground after settling at night. In the morning, in addition to automobile exhaust emissions, there is carbon monoxide pollution. In addition, fog is easy to appear in the early morning in winter. Dust, bacteria, pathogenic microorganisms and amines in fog droplets are dozens of times that of normal atmospheric water droplets.
In order to achieve better exercise effect, we should follow the growth and decline law of spring, summer, autumn and winter, and carry out corresponding physical exercise according to the seasonal characteristics of spring, summer, autumn and winter. Therefore, winter sports should conform to the laws of nature and the healthy concept of "going to bed early and getting up late, we must bask in the sun". The time for winter exercise should be after sunrise. In addition, different people should also choose appropriate sports, such as: young people should choose fitness, aerobic dance and other sports; Middle-aged and elderly people should choose brisk walking, jogging, Tai Ji Chuan and other sports. Winter sports should adhere to the principle of gradual and persistent, and arrange the amount of exercise reasonably. Choose a suitable sports ground, and try to choose a sports ground with broad vision, moderate hardness and flatness.