The air is fresh in the morning, but if you exercise too early, the oxygen content in the air is low, especially in the Woods, which is not suitable for exercise. So 5: 00 to 7: 00 in summer is the best exercise time. Around 4 pm, the oxygen in the air is the most abundant, and the best time for exercise is 14: 00 ~ 19: 00. Human activities are controlled by the biological clock, so it is more beneficial to health to arrange exercise time according to the law of the biological clock. Fitness in winter is best between 14:00- 19:00 in the afternoon. At this time, the outdoor temperature is relatively high, and the temperature of the human body is relatively high, and the physical strength is relatively abundant. It is easy to get excited, and it is easier to enter the state of exercise. Afternoon: (14: 00 ~ 16: 00): It is a good opportunity to strengthen physical strength, and the muscle endurance is 50% higher than other times. Dusk: (17: 00 ~ 19: 00): Especially when the sun goes down, the human body's exercise ability reaches its peak, and the vision and hearing are more sensitive, and the heart rate and blood pressure also rise. Not suitable for after-meal exercise: at this time, more blood flows to the gastrointestinal department to help food digest and absorb. At this time, exercise will hinder the digestion of food, and over time, it will lead to diseases of the gastrointestinal system and affect health. Therefore, it is best to sit still or lie down for 30 ~ 45 minutes after meals and exercise. After drinking: alcohol is absorbed into the blood and enters the brain, heart, liver and other organs. At this time, exercise will increase the burden on these organs. Compared with after-dinner exercise, drinking exercise has a greater negative impact on the human body. Scientists have found that 3: 00 to 6: 00 pm is the most suitable prime time for exercise in human physiological cycle, because under the command of the rhythm of brain physiological cycle, at this time, human body temperature is at the highest point, muscles are the warmest and most elastic, people are quick-witted, strong and not easy to get hurt, while pulse beating and blood pressure are the lowest. The average person's body temperature is the highest from 2 pm to 4 pm, and then it begins to drop. On the contrary, the body temperature is the lowest within 3 hours before getting up in the morning. If you exercise, you can't achieve the best results. However, health experts believe that there is no need to worry about the difference in body temperature, and it is more important to seize the time you can allocate to exercise. The American Sports Association gives the following advice to athletes: If morning exercisers like to exercise in the morning, they'd better stick to it instead of after work, because obviously you are a person who will be dragged down by work and can't find time to exercise. You need to pay attention to do enough stretching and warm-up exercise before exercise, because the body temperature is still low in the morning, which is easy to get hurt and is not good for the heart and blood vessels; From the perspective of physiological science, afternoon exercisers undoubtedly have the best opportunity, the best physical response and the softest muscles. Relax your family. If exercise is to relieve stress, it is appropriate to do relaxing exercise at any time. Night owls try to exercise 3 hours before going to bed. Exercise too close to bedtime may be bad for the heart, or it may be difficult to sleep because of excitement.