Part 1 Sleep Series: The Importance of Sleep Cycles

We know sleep is essential.  Sadly, we often don’t get enough, or understand why sleep is so important to our overall health.  In this content series on sleep, we will delve into the amazing benefits of the 90 minute repetitive sleep cycle, learn more about the circadian rhythm, discover our own personal sleep chronotype and see how we can improve our sleep.

So, let’s talk about sleep cycles.  Sleep is divided into two different types: rapid eye movement (REM) sleep and non-REM sleep.  These two play out in a cerebral cycle every 90 minutes throughout the night.  What is happening in the brain? And what is the impact on your health?

Neuroscientist sleep researcher and author of Why We Sleep, Matthew Walker, explains what happens to our body as we go in and out of these stages of sleep.  Shortly after we fall asleep, in the light stages of non-REM sleep, our heart rate and blood pressure drop.  Our brain activity also begins to slow down.  Then, in the deeper stages of non-REM sleep, the brain explodes into activity.  Brain cells in the cortex fire up together, then go silent together.  Walker calls the deep brain waves a “ballet of coordination” that is not completely understood.  Still, science has been able to recognize the many benefits of non-REM sleep on the brain and body.  

• Strengthens and consolidates memory of what was learned during the day.  It’s like a mechanism to transfer files of memory into a safe place where they are less likely to be forgotten.

• In the deeper stages of non-REM sleep, the cardiovascular system cycles down.  It is a shift from the fight or flight mode in our nervous system to what is called the quiescent branch of the nervous system.  This provides cardiovascular benefits such as a lowering of blood pressure and heart rate.

• During deep sleep, the immune system function is improved.  We restock our arsenal to fight disease by increasing the amount of immune factors in the body, as well as increasing our sensitivity to these immune factors.  These mechanisms help us fight against unwelcome invaders in our body such as cancer, viruses, and harmful bacteria.

Next in the sleep series:

What is REM sleep and how does it help

me function?