1. According to medical theory, it is advisable to go to bed late and get up early in spring and summer, and sleep for 5 to 7 hours every day; It is advisable to go to bed early and get up early in autumn, and you need to sleep for 7-8 hours every day. It is advisable to go to bed early and get up late in winter, and you need to sleep for 8-9 hours every day, which conforms to the law of natural growth and collection.
2. Sleep is a normal physiological need, but the longer you sleep, the better. People of different ages have different needs for sleep time. The younger the age, the lower the excitability of the cerebral cortex, the worse the tolerance to fatigue, so the longer the sleep time is needed.
3. The function of cerebral cortex in the elderly is not as active as that of young people, and their physical activity is greatly reduced, so the time required for sleep is correspondingly reduced.
4. Some elderly people often sleep for more than 5 ~ 6 hours every day, but they still feel sleepy from time to time, mainly because the elderly really don't have much time to reach deep sleep and moderate sleep, but most of the time is spent in shallow sleep and shallow sleep, so the quality is not high.
In real life, many people sleep much less than the above time, but their work and life are very good. Therefore, the quality of sleep does not depend entirely on the time of sleep, but on the quality of sleep, that is, the length of deep sleep throughout sleep.
6. The quality of sleep should not be simply measured by the length of sleep, but by whether fatigue is eliminated and whether energy is abundant.