Important English is: important, significant, main, promotion.
Health preservation can be expressed as: keeping fit, keeping healthy, keeping healthy.
There are many important factors to keep healthy, but I think the most important factor should be regular work and rest. I remember a famous physician in ancient times once said that the secret of his health preservation was to sleep. Keeping a reasonable sleep is his single most important way to keep fit. If you don't sleep for a day, you can't make up for it for half a year.
This shows the importance of sleep. Regular sleep can help us adjust our physical condition. According to scientific research, after entering the sleep state, the human body will secrete a substance called melatonin, which can not only help us adjust the endocrine balance, but also play a good role in resisting many diseases.
Even has a very good resistance to a variety of malignant diseases, so maintaining a regular work and rest is one of the most important standards to maintain good health.