Have you heard of slow-wave sleep?  More often called "deep sleep," slow-wave sleep is that crucial stage of sleep when we both burn fat and build muscle.


Bottom line: without adequate sleep, you'll have a difficult time slimming down the body.  What's worse: a lack of sleep tends to generate more fat-storing hormones like cortisol - which will completely undo all your workout efforts.


How getting too little sleep makes weight loss nearly impossible 


Sleep is when we restore the body and mind, I know you’ve heard this old adage.  But like many old adages, this one has a lot of truth to it. 


When we don’t get enough sleep all our fat storing hormones become elevated, like insulin and cortisol.  Furthermore, two hormones that make us super-hungry - and hungry for fat, sugar, and fried foods (aka fast food and convenience sweets!) called leptin and ghrelin, also become elevated - making it harder and harder for us to keep driving past those Golden Arches every day. 


Furthermore, since slow-wave sleep is the time when we repair and build muscles after exercise and when we dip down into our fat stores and burn fat (because we’re fasting), we can wake up to the same body day after day, even though we’re working out and dieting harder than ever! 


What are the five sleep cycles? 


Slow-wave sleep is also called "delta wave sleep" and this happens in two cycles right before our final cycle of REM sleep (rapid eye movement sleep). 


Stage one: Light sleep (this is when we’re falling asleep and will most easily awaken if disturbed. 


Stage two: Brain waves spike now, into what is called “spindles,” and we fall more deeply asleep. This is when you want to wake up after a nap, at the end of stage two sleep to feel somewhat refreshed. 


Stages three and four*: Deep sleep, slow-wave sleep or delta wave sleep. This is when the body and mind reset.  The brain forms memories, the body secretes growth hormone (GH) which helps us form muscles and burn fat, and we balance hormones and manufacture mood-balancing neurotransmitters - which is why a lack of sleep makes us grouchy. 


REM Sleep. This is when dreaming occurs and the body actually paralyzes the limbs, so you don’t try to “act out” these dreams. The body enters a stage of pseudo-wakefulness, which is why the eyes begin moving rapidly. Some memory consolidation, researchers believe, happens both during slow wave and REM sleep. 


Every 90 minutes, you enter a cycle of REM sleep, during an average night’s sleep. This means you can experience 5-6 slow-wave sleep cycles or more on a night you sleep 8 to 9 hours! 


The body does let you make up sleep - to some extent!


Interestingly enough, although you’ve probably heard that you cannot make up lost sleep, researchers have actually found that if you lose deep sleep one night, the body more quickly moves through the early sleep stages so that you can get more deep sleep the next time you sleep! 


Key point: We need a lot of slow-wave sleep 


We need five or more cycles of slow-wave sleep a night to keep the body maximally healthy and to complete important physiological processes like brain repair, memory formation, and the manufacturing of hormones and neurotransmitters that keep our hormones in balance and keep our mood elevated and up! 


The truth is: a lack of slow-wave sleep is strongly linked to serious health problems.


In fact, a lack of slow-wave sleep has been directly tied to:


* Obesity 

* Hypertension and heart disease 

* Type 2 diabetes 

* Alzheimer’s and other neurodegenerative diseases 


So, get that 8 or 9 hours of sleep a night. Your brain and your body will thank you in all kinds of healthy ways! 


Sources for this article include: 

 

NIH.gov

NIH.gov

Oup.com

NIH.gov

NIH.gov

NIH.gov


*Some researchers and sleep specialists divide slow wave sleep into two stages, stages three and four, and some just call this “Stage three sleep.”