The body’s clock regulates sleep by producing the hormone melatonin at night and switching it off in the presence of light. There are four stages of sleep that the body experiences in cycles throughout the night, and cycling through them four or five times is optimal. Sleeping less than seven hours per day is associated with increased risk of chronic illness and reduced life expectancy, making it important to get enough sleep for a healthy, long life.
- (00:00:00) In this section, we learn that sleep is regulated by the body clock, which responds to light, ramping up the production of the hormone melatonin at night and switching it off when it senses light. There are four stages of sleep that the body experiences in cycles throughout the night, and on a good night, we cycle through these stages four or five times. Sleeping less than seven hours per day is associated with an increased risk of developing chronic conditions which could reduce life expectancy, therefore it is important to get enough of it for a healthier, longer life.