Sleeping is asked by the university! As the saying goes, going to bed early and getting up early is good for your health. There is only one concept, no quantification and no meaning. The key to sleep quality lies in deep sleep. It can be said that only 2~3 hours of sleep is enough. Usually 0 to 3 o'clock is the time for deep sleep, but you can't go into deep sleep as soon as you fall asleep. There is a transition period, usually 1~ 1.5 hours! Conversely, it is best to go to bed from 22: 30 to 23: 00 to prepare for a deep sleep! When do you get up? Internationally recognized is 6 o'clock. In addition, in line with the changes of natural seasons, the recommended work and rest time is: 22: 00 ~ 23: 00 in summer-> 6: 00 ~ 7: 00 in sleep-> 21:30 ~ 22: 30 in winter-> Fall asleep at 6:30-7:30-> At noon, people's alertness is declining. At this time, taking a nap helps to restore the spirit and is good for work, study and health. In addition, dinner should be finished two hours before going to bed, because growth hormone reaches its peak at night, and eating midnight snack will affect the secretion of growth hormone, thus affecting the growth of the body. If you are really hungry, you can eat something high in protein, such as eggs, bean products and milk. Second, how long is the best sleep time for all ages, as follows: 20 hours for newborns, 8 hours for preschool children 14- 15 hours for pupils 12 hours for middle school students 10 hours for college students, 8 hours for adults and 8 hours for the elderly. 6-7 hours is too long and too short, 7-8 hours is suitable! A study conducted by scientists shows that if people spend too much time in bed every night, its impact is just like sleeping too little, which will lead to many sleep problems. For example, people who sleep more than 8 hours and less than 7 hours a night complain that they have sleep problems. People who sleep seven to eight hours a night have fewer sleep problems. I also believe that many people have this experience: once they sleep late, they feel groggy and don't want to get up. The more you sleep, the more groggy you are. You spent your last day in a daze and couldn't sleep at night! If you want to have a good sleep, you must control your time! At the same time, we should adjust the length according to the season, sleep less when the summer nights are short, and sleep more when the winter nights are long and cold! Sleep 7~8 hours in summer and 8~9 hours in winter! On this basis, children will increase 1~3 hours, and the elderly will decrease 1~3 hours.