People are used to thinking that morning is a good time for exercise. The existing research data show that "morning exercise is not a good time". First of all, the air in the morning is not fresh. In most mornings of the year (especially at 5-8 o'clock), an inversion layer will appear in the lower atmosphere over the land, with a height between 200- 1000 meters. Like a hood, let more smoke and impurities in the city gather under it. In addition, the air disturbance is small in the morning, and it is difficult for smoke and dust impurities to spread to the upper air and surrounding areas, which leads to the aggravation of the air near the ground.

Secondly, from a physiological point of view, experts' research on the characteristics of human biological clock rhythm shows that the sugar content in the liver is the lowest in the morning, and if physical exercise is carried out during this time, the energy of exercise-sugar will be mainly supplied by fat decomposition. After fat enters the blood as an energy substance, the concentration of free fatty acids in the blood increases significantly because the human body cannot effectively use the free fatty acids in it. Some scholars have investigated patients with a history of heart disease and found that medical statistics show that the early morning is not only the peak time of heart attack, but also the time of sudden death, and the incidence rate accounts for 6 1.3%. It is three times higher than around one o'clock in the afternoon. This is mainly because the blood is thick in the morning and it is easy to form blood clots. Doing strenuous exercise is also easy to cause bumps, bruises and sprains.

Of course, it is not to let everyone give up the opportunity to exercise in the morning. For college students, it is still extremely effective to keep exercising 10- 15 minutes after getting up every morning, which can eliminate the "stagnation" phenomenon of human tissues after a night's sleep, enhance the endurance of the whole body, glow the mood of studying for a day and improve the learning efficiency. Such as radio exercises, aerobics, jogging, playing Tai Ji Chuan and practicing martial arts are all good exercises.

2.2 Exercise during extracurricular activities in the afternoon

According to the circadian rhythm of the human body, the best time is 5 pm, near dusk. At this time, most people's physical strength, flexibility, coordination, accuracy and adaptability are at their best. Moreover, the sugar in the human body has also increased to the peak, and there will be no energy metabolism disorder and organ function overload when carrying out various fitness exercises.

There are several reasons why people behave physically at dusk or at night. For example, many training performances are closely related to body temperature. The body temperature is the highest at dusk and evening (during the day, the body temperature usually changes in the range of 1 to 2 degrees Celsius, and reaches the lowest at 5 am). Studies also show that human body temperature is the highest at dusk. Since the research has found that this kind of physical fitness changes very little, unless you are a competitive athlete, it will not have much influence on you. For competitive athletes, small changes in physical fitness will affect whether they can reach the best level. By the way, when you are preparing for the competition, experts suggest that the best training time is the same as the competition time. This can make your body rhythm more suitable for this time and environmental factors. (such as outdoor temperature and pollution level).

2.3 Physical activities before going to bed

Exercise before bed is also very effective. This is because the role of physical activity before going to bed can be maintained throughout the sleep process, especially doing some exercises to deepen breathing, such as moving diaphragm or dilating thoracic artery. This kind of exercise can make the whole system of human body oxygenated. People who are in a more aerobic state not only have a good sleep, but also greatly accelerate the speed of relieving daytime fatigue and make their bodies recover well. Especially for people with insomnia, exercise before going to bed is a necessary condition to cure insomnia. The heat discharge brought by bedtime activities can not only regulate the metabolism of the whole body, but also restore the benign fatigue after exercise through a night's sleep. Especially taking a bath after exercise before going to bed will make you fall asleep very comfortably, which is undoubtedly the best way for neurasthenia patients to fall asleep. Exercise items such as walking, doing exercises, sit-ups, pull-ups, standing long jump, push-ups and so on.

3. Grasping the intensity of exercise is more conducive to your own exercise. Here's how to control the intensity of exercise by measuring the pulse.

The exercise intensity of pulse per minute 160 is about 80%;

The exercise intensity of pulse per minute 140 is about 70%;

The exercise intensity of pulse per minute 120 is about 60%;

The exercise intensity of pulse per minute 1 10 is about 50%;

Studies have proved that people whose exercise intensity is less than 50% have no obvious exercise effect, while those whose exercise intensity is more than 80% belong to the intensity of exercise training. For the average person, it is appropriate to control the pulse during physical exercise between (1 10- 160) times/minute. Everyone should choose suitable sports activities and time according to their own reality, pay attention to practical results and be practical. When choosing the content of physical exercise, we should make corresponding arrangements with the change of seasons. We don't have to make a decision once and then try for a while. We can adjust or change it if necessary, but we shouldn't change too much. After making your own exercise plan, you should consciously abide by it and persevere.