Why is it easy to get up early in summer and difficult to get up early in winter?

First of all, because of the influence of light.

Dawn comes early in summer and late in winter. Light can affect our sleep by affecting melatonin in our body.

The main function of melatonin is to improve sleep, and its secretion has obvious circadian rhythm, which is inhibited during the day and active at night. It is easy to get up early in summer, with less melatonin secretion and less sleep. In winter, the dawn is late, melatonin is reduced late, and sleep is just right, so it is difficult to get up early naturally.

The second is because of the difference in ambient temperature.

In summer, the temperature is high, the temperature difference between the inside and outside of the quilt is not big, and even it is very cold outside, so it is easy to get up early; In winter, the quilt is warm inside and underground outside. In this case, people are often in warm places, so it is not easy to get up.

The third is because of the indoor carbon dioxide concentration.

High carbon dioxide concentration will slow down human metabolism and make people sleepy.

In summer, we usually sleep with the window open, and the indoor carbon dioxide concentration is low; In winter, doors and windows are usually closed to keep warm. After a night's breathing, the concentration of carbon dioxide is high, which makes people sleepy and difficult to get up.