It is a blessing for those who can eat and sleep, which is enviable. Sleep well, the brain is good, and sleep is only effective.

　　The great revolutionary mentor Lenin said : "If you don''t rest, you won''t work." The human body has Zhang Youchi, and the human brain has excitement and suppression. If you do not sleep well at night, you will yawn day after day, languish, lack of energy, inability to concentrate, slow response, and physical strength will also drop significantly, which will inevitably affect the efficiency of work and study, production workers, lack of sleep, inaction Coordination reduces production efficiency, and the rate of defective products rises.

　　The lack of sleep for R&D, design and creative workers will lead to upset, decreased passion, exhausted thinking, and in vain. Normal sleep is a physiological phenomenon in which the human body relieves fatigue, restores physical strength and brain power, and is conducive to work and study. Lack of sleep and excessive sleep will have a negative impact on intellectual development.

　　In the early 20th century, the average daily sleep time was about 9 hours. By the beginning of the 21st century, people''s average sleep time was only 7 hours, a decrease of 2 hours. And because of overtime, watching TV, surfing the Internet, playing games, and various other entertainment activities, many people can only have 4 to 5 hours of sleep a day, which seriously affects people''s metabolism and reduces the body''s immunity. Over time, it will affect People''s health, which in turn affects people''s lifespan.

　　Scientific research proves that adults need to maintain 7 to 8 hours of sleep every day, so as to ensure the normal metabolism of the body, and the immune system and brain can be repaired in time to ensure that the body is healthy and full of vitality. To achieve the purpose of extending people''s life. Sleeping for too short or too long is harmful to human health and longevity.

　　The following is the changing process of sleeping time from baby to the elderly, for readers’ reference:

　　newborn period: about 20 hours Infant period: about 13 hours

Pre-school children: about 10 hours School-age children: 9~10 hours

　　Young people under 20 years old: about 9 hours Adults: 7~8 hours

　　 seniors: 5~7 hours Over 80 years old: 8~10 hours