Zhang Chaoyang said that sleeping four hours a day is enough. Why?

Recently, Zhang Chaoyang, Chairman and CEO of Sohu Board of Directors, said in the live broadcast that the first two hours of sleep are deep sleep, and after three hours, people's brains begin to have various nightmares. In the process of having nightmares, people have no reason to control them, so why do we often sleep badly is because we spend it in nightmares. Sleeping too much is harmful to people. I suggest you sleep less, preferably six hours. It would be perfect if you could sleep for four hours.

How do adults sleep in China? The Healthy China Action (20 19-2030) shows that the average sleep time of Chinese adults is 6.5 hours a day. In this regard, the Healthy China Action proposes an advocacy goal: from 2022 to 2030, the average sleep time of adults should be maintained at 7 to 8 hours per day.

Li Ning, a senior clinical expert in the Department of Neurology, xuanwu hospital, Capital Medical University, said that newborn babies may sleep for about 20 hours every day besides drinking milk. According to normal age, infants may sleep more than 10 hour, and primary schools generally sleep about 8- 12 hour; Teenagers usually sleep 10 hour; Adults basically sleep for about 7-9 hours; After old age, with the degradation of the body, some neurotransmitters in the brain will decrease, and the corresponding sleep time will also decrease, and sleep will be about 6 hours.

Studies have shown that long-term lack of sleep will increase the risk of cardiovascular and cerebrovascular diseases, depression, diabetes and obesity, and damage cognitive function, memory and immune system. There are more than 80 kinds of sleep-related diseases.

Experts point out that it is scientific basis for adults to keep sleeping for 7 to 8 hours, which is also the most beneficial to health. However, due to various reasons, most people's sleep time is shortening, and the prevalence of sleep disorders, especially insomnia, is on the rise.