Physiologically, the human body just woke up from a deep sleep in the morning. At that time, your whole body's blood flow rate and the activity function of organs were relatively low, and your whole body's muscles were basically relaxed for one night, and they have not returned to normal. At this time, when you run in the street, it is easy to cause hypoglycemia. Even if you eat something, because the internal organs have not returned to normal work and can't provide you with energy well, it is easy to cause insufficient blood supply.
In addition, there is another disadvantage. Because the organs have not fully recovered, the lungs and other internal organs still have a running load. Generally speaking, it's not a big problem, but getting up in the morning is easy to cause visceral overload, especially after exercise, which makes the blood vessels unbearable, so the incidence of cardiovascular and cerebrovascular diseases will be high in the morning. That's the reason.
At night, it's different. At night, all the organs of your body haven't started to rest. Going out for a run at this time, the pressure on the body is not great at first. The above content has no effect on your evening. Besides, the air at night will be better than in the morning. Some people may not understand that the air is fresh in the morning, not because of the air, but because of the humidity in the air
In fact, the concentration of carbon dioxide in the air is the highest in the morning. Everyone knows that photosynthesis needs light. At night, plants can't carry out photosynthesis and can only breathe. At this time, not only humans will emit carbon dioxide, but also plants will emit carbon dioxide. After dawn, plants can absorb these carbon dioxide through photosynthesis, so the concentration of carbon dioxide is the highest in the morning. In the evening, plants have a day of photosynthesis, which can be said to be the lowest carbon dioxide concentration.
The concentration of carbon dioxide shows the concentration of oxygen, so running at night is healthier than running in the morning.