For office workers, it seems that they have to take a break at noon and have mental work in the afternoon. Especially during weekends and long holidays, many people spend most of their time in bed and "improve immunity" by supplementing sleep. However, some people will feel "the more tired they sleep after a nap" and "it is difficult to fall asleep at night". So, can we take a nap? What are the benefits of siesta? 1. Improve work efficiency. During sleep, the nerve cells in the cerebral cortex are protected and rested, and all parts of the body are also rested accordingly, so that the physical strength consumed by activities can slowly recover. So napping is an excellent way to recharge the brain and improve work efficiency. 2. Promote tear secretion. After you close your eyes and fall asleep, the ciliary muscles of the eyeball can have a full rest, and the lacrimal gland begins to secrete tears to moisturize the dry eyes and relieve fatigue. 3. Repair skin barrier. When sleeping, the consumption of muscles and internal organs is reduced, the skin blood vessels are completely opened, and the blood can fully provide nutrition for them, and carry out self-repair and cell renewal. The metabolism of skin is most vigorous in sleep. Not all people are suitable for napping. For ordinary people, a 20-30 minute nap can improve the quality of sleep at night. First, the sleep cycle is divided into five stages. The first two stages are relatively shallow sleep, the third and fourth stages are deep sleep, and the last stage is the rapid eye movement stage, which is the stage to start dreaming. The first two stages occur within 30 minutes. If you wake up in the first stage, it makes you feel like you haven't slept. In the second stage of sleep, the brain begins to integrate and process the declarative memory to consolidate the memory. Therefore, a reasonable nap is to start from the first stage of sleep, enter and stay in the second stage, and avoid entering the deep sleep stage. Second, if you sleep for a long time, the central nervous system of the brain will cause the capillaries of the brain tissue to close for a long time, and the metabolism process in the body will also slow down. After waking up, all tissues and organs of the body will be forced to wake up, which will cause the feeling of general fatigue. But for insomniacs, siesta will reduce the driving force of sleep at night, so siesta is not recommended. This is the reason why "I have insomnia. Why don't doctors let me take a nap instead?" It is a way to improve sleep efficiency by reducing the non-sleep time spent in bed. (Xinhua News Agency)