Your 24-Hour Sleep Cycle Explained

by Martin Reed Patient Advocate

Your body clock has a huge influence on daytime energy levels and how well you sleep at night. Being more aware of your body's natural rhythm enables you to pinpoint the time of day you're best at certain tasks, leading to a happier, healthier life.

Woman waking up and stretching.
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6 a.m. to 9 a.m.

This is usually the ideal time to wake up. Your body stops producing melatonin, a signal that it’s time to get active and start the day. However, this a poor time to exercise since your blood pressure is often at its highest.

Productive meeting in an office.
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9 a.m. to Noon

Between these hours you are at your most alert. Your body is producing the highest amounts of cortisol, giving your brain a boost. Your short-term memory is at its peak and you are at your most productive.

Woman falling asleep at her desk.
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Noon to 3 p.m.

This is when most of us eat our lunch. The subsequent increase in digestive activity can lead to a drop in alertness and the familiar urge for a daytime nap. Drinking alcohol at this time can make you especially drowsy.

Man exercising in a gym.
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3 p.m. to 6 p.m.

Your body temperature naturally increases in the late afternoon and your heart, lungs and muscles are at their peak level of performance. This is the perfect time to get in your daily exercise.

Friends toasting at dinner.
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6 p.m. to 9 p.m.

This is probably the time when you'll eat your biggest meal of the day. Try to reduce the size of your meal the closer you get to your bedtime . Your liver is best prepared to process alcohol at this time.

Woman woodworking at night.
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9 p.m. to Midnight

Your core body temperature is beginning to fall and melatonin production increases, signaling to the body that it will soon be time to sleep. For most of us, this is the ideal time for bed. Interestingly, this may also be your most creative period of the day.

Woman struggling to stay awake while working at night.
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Midnight to 3 a.m.

Your brain is busy clearing out toxins and consolidating memories. Melatonin production is hitting its peak. If you are still awake, your attention levels will be extremely low.

Woman sleeping soundly at night.
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3 a.m. to 6 a.m.

Melatonin levels begin to fall and your core body temperature reaches its lowest level. By this time you have probably got all of your deep sleep since this tends to occur earlier in the night.

Man sleeping while holding his alarm clock.
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Adjusting your cycle

Although these stages of the sleep/wake cycle are typical, we are all different. If you're a 'morning person', you're likely to be at your most productive early in the day. If you're an 'evening person', you'll typically wake later and hit your most productive stage later in the day, too.

Martin Reed
Meet Our Writer
Martin Reed

Martin is the creator of Insomnia Coach, an eight-week course that combines online sleep education with individual sleep coaching. His course helps clients improve their sleep so they can enjoy a better life with more energy and start each day feeling happy, healthy, rested, and refreshed. Martin also runs a free sleep training course that has helped over 5,000 insomniacs. He holds a master’s degree in health and wellness education and studied clinical sleep health at the University of Delaware.