The Sleep Wake Cycle

Have you noticed that you tend to feel drowsier in the evenings and more awake in the
mornings, even if you haven’t slept well?

Circadian rhythm

Our bodies have a natural sleep wake cycle which is referred to as our circadian rhythm. In most people the optimum cycle is to sleep for between seven and nine hours at night and to be awake for 15 to 17 hours during the day.

Our bodies secrete certain chemicals and hormones as we pass through different stages of the sleep wake cycle.


One of these is adenosine which begins to accumulate in your blood throughout the day.
The longer you are awake, the more adenosine you have in your blood until you reach the point where the levels are so high that you need to go to sleep when they start to fall again. As a mum it can be difficult if your body is telling you it’s time to sleep but your children are still awake. Caffeine blocks adenosine receptors, which is why some people drink coffee to help them stay awake.


Melatonin is another hormone that regulates when we sleep and wake. Levels naturally increase from the late afternoon and throughout the night, falling in the morning. If you use bright screens in the evening and night-time it can disrupt melatonin production and make it harder to sleep, which is why it’s not recommended.

A disrupted cycle

If you are a shift worker, your natural circadian rhythms get disrupted by your irregular working hours, which can be difficult. Turning on a bright light when it is time to wake up and using blackout curtains when it is time to go to sleep may help.

For more great tips on getting a good night’s sleep browse our Blog categories: Live – for general lifestyle advice; Sleep – for specific information about sleeping and the conditions needed for good quality sleep; and Relax – for information to help you unwind and quieten your busy mind. Also check out our Product pages for tried and trusted products to help you sleep.

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