Is the air good in the morning or in the evening?

The air is good at night, and you should surf the internet for running and exercise. Summer is not suitable for running, and it is easy to get heatstroke.

Because plants can only breathe at night, absorb oxygen and exhale carbon dioxide, so the oxygen concentration is the lowest and the carbon dioxide concentration is the highest in the morning.

But during the day, plants both breathe and photosynthesis, and the intensity of photosynthesis is greater than breathing, so plants absorb carbon dioxide and release oxygen. So at night, the oxygen concentration is the highest and the carbon dioxide concentration is the lowest. So it is suitable for running at night and healthier.