How Sleeping On Your Back Can Ruin Your Ability to Breathe, Get Oxygen To Your Brain, and Shorten Your Lifespan.
Look at the image above — which do you believe to be the best sleep position?
I show this image in workshops and during keynote speeches, and it always has a mind-blowing effect when I share the science.
To start, the best sleeping position is “D” — in other words, on your stomach, AND without a pillow.
Yes. Without a pillow.
And yes…on your stomach.
I’d like to share the science behind both of these statements, and more importantly, how any other position may be negatively affecting your sleep (and worse, affecting your health).
Most sleep strategies proposed have quite the opposite effect of assisting with a good night’s sleep.
Whether it is “ergonomic” pillows, the fallacy that sleeping on your back is preferred, or tools that assist in getting “in alignment” overnight, there is always a new “thing” that is going to help you sleep better.
Usually these products are designed without someone who understands neurodevelopment, spinal mechanics, or basic physiology.
More often than not, these products are developed and motivated by profiteering rather than pioneering health solutions.
They often have the cumulative effect of decreasing oxygen overnight, contributing to chronic reduced oxygen to the brain, destroying the natural curves in the neck, and assisting with muscular degeneration.
That is why I have written this article.
To provide some clarity on best practices for sleep hygiene and health.
Upon an examination of the literature, as it relates to longevity, disease prevention, and brain health, not all sleep positions are created equal.
In fact, the position most often touted as the one to avoid, stomach sleeping, can offer the most benefit in terms of opening the airway, improving diaphragmatic breathing, lowering the workload of the heart overnight, and improving oxygenation.
Sleeping On Your Back Causes Hypoxia (Low Oxygen)
“Laugh and the world laughs with you, snore and you sleep alone.” — Anthony Burgess
Often touted as the preferred way to sleep, sleeping on your back can do more harm than good.
If we rewind for a moment and look at the neurodevelopment of children, the way they develop curves in their spine is primarily through tummy time.
Parents are always hearing the importance of tummy time.
As they should.
Initially, tummy time functions primarily to develop the strength of the axial musculature so baby can lift her head up.
Once she is able to do this, she will start panning her eyes along the horizon and rotate her head from side to side.
More specifically, it is the rotation of her head from side to side whilst on her belly that will develop the curve in her neck.
If we break down these two movements:
- lifting her head (extension) and
- looking off to the side (rotation)
This is how the joints of spine grow to have the angles and articulations they do.
It is through tummy time that we develop the muscles that extend and rotate the head on the neck, thereby allowing for proper curve development to happen.
So if tummy time is important for kids to develop a curve, shouldn’t it be important for adults to maintain it?!
Do you even tummy time, bro?
This is precisely why stomach sleeping is important, and my preferred sleep position for longevity and vitality.
Sleeping prone is the one thing as adults, that put our heads simultaneously in extension and rotation on a daily basis.
The position that will help us maintain the necessary curve in our neck.
Stomach sleeping is the only time where we can undo the prolonged flexion of our head, open up our airway, train our diaphragm to be strong, and improves nasal breathing.
Now I can go on a nerd safari on why having a proper cervical is important… but that is a whole other animal.
For brevity for those that are not familiar with the importance of a sound cervical curve, here is a brief, and I’m sure incomplete list that having a cervical curve assists with:
- Cerebellar function
- Forced Vital Capacity
- Heart rate
- Vestibular Apparatus Activation
- Spinal Cord Function
- Mortality Rates
- Range Of Motion (especially lateral flexion an rotation)
- Just Good Old Pain Vanity: Nice Posture
- Prevention of Gibbus Deformity
You get it.
Having a curve is important.
Sleeping with a pillow behind your head does the opposite — it destroys your cervical curve over time.
The issue I take with a pillow under our head is this: during the day we are already always in flexion.
Think about it.
How many hours do you spend driving, on your computer, on your phone, or sitting in any given day?
The average American now sits for 12–16 hours a day.
And if you say, but doc, I exercise and go to the gym!
However,if we think of the most typical cardio machines…how many of them only train you with movements going only forward and backwards?
Treadmill —legs and arms are moving forward and backwards
Elliptical — ditto
Bike — samesies
Stairclimber — still forward and backwards
They are all working the sagittal plane.
Which is what we do at the desk, in the car, and on our phone…we stay midline.
To add insult to injury, there is usually a TV integrated into the machine so our heads are down anyways while we are using these machines.
We NEED to move our heads side, just like we need to move our bodies side to side.
Health and vitality lives in the coronal plane.
In other words, movements that go side to side, away from the midline..
Think jumping jacks, squats, warrior pose, lateral arm movements, or dancing (assuming you dance like me and your arms are everywhere)
Similarly, when we are sleeping, if we do NOT move our heads side to side and just keep it propped up and flexed….I can confidently say goodbye to your cervical curve…and with it, some of essentials relay and feedback systems to the brain.
Stomach sleeping is the equivalent of adult tummy time.
When you think about the time you spend in the midline…you will begin to realize how much you need it.
If sleeping on your stomach is uncomfortable, you need to find way to restore the curve in your neck.
Easy ways to do this are to get under chiropractic care coupled with muscular rehabilitation to restore proper rotation, lateral flexion and extension.
Another unpleasant side effect of back sleeping is mouth breathing.
Like to wake up like you slept with a sock in your mouth and chapped lips?
Yea. Me neither.
While it may seem like amusing to read urban dictionary’s definition of a mouth breather , it isn’t that far off given a supine sleeper is someone who is cumulatively not getting enough oxygen into their body.
Over time, this will lead to decreased oxygenation of the brain and body.
It would be a reasonable assumption this could affect brain function over time.
The Pillow Fallacy
“That nice, soft pillow and the warm blanket, and it’s all comfortable, and no one wants to leave that comfort — but if you can wake up early in the morning, get a head start on everyone else that’s still sleeping, get productive time doing things that you need to do — that’s a huge piece to moving your life forward. — Jocko Willink
I always chuckle just a wee bit when I see products, in particular cervical pillow products, that tout “natural alignment” at night.
First, alignment can only be measured when someone is standing UPRIGHT, against gravity.
NOT while lying down on your side.
For my neuro nerds, the reason you need to be upright to asses alignment and not on your side is because we engage the Vestibulo-Ocular Reflex, the Pelvo-Ocular Reflex, the Vestibular system, and compensatory patterns of the neuromusculature. We can also see left and/or right brain weakness with eye movements, and pupillary symmetry.
But, let’s assume for a moment these basic physiological occurrences didn’t exist and let’s pretend we really could evaluate alignment in side posture.
This picture isn’t really aligned at all, is it.
- I see a head that flexed forward, thereby continuing to exacerbate and diminish the necessary curve in the neck.
- I see a cervical pillow putting excess pressure on one side of the jaw (hello TMJ problems).
- I see one shoulder that is internally rotated and shoved forward.
- I see hips that are not really aligned with the spine.
Even the alignment line itself appears to be tilted downwards towards the hips.
Let’s look at another variation of the same idea. Back sleeping.
Sleeping on your back with a pillow of any kind is going to bring your head forward overnight…the same position your head tends to stay in all day when you are hunched over your computer.
No biggie, right?
The thing is, there is physiological process called creep.
Creep is the consistent deformation of ligaments and musculature when placed in a static, non moving position.
In other words, your muscles, bones, and ligaments will start to assume your bad sitting posture even when you are not in those positions.
Putting a pillow under your head, (whether you are on your back or side) is just reinforcing the creep.
Meaning, your text neck, will start to want to assume that position even when you are not texting.
What that means is, the curve in your neck will begin to flatten, and in many cases, it reverses over time.
With it, adding extra forces to the bones and discs so they degenerate too.
Bone spurs develop, functional range of motion is lost, and your left looking someone who works in a bell tower, with no ability to turn their heads left or right.
This supports the idea of NOT using a pillow as it will continue to deform your neck.
Pillows do the exact opposite of what you think they are doing.
They add more deformation, and more degeneration, and more problems long term.
In Defense of Stomach Sleeping
“I sleep on my stomach with my head under a bunch of pillows so if someone wants to come in and try to kill me they can’t tell if I’m there or not, so they’ll just leave.” — Wiz Khalifa
Sleeping, since it represents about a ⅓ of your day, can be a wonderful way to undo the text neck, the excessive flexion whilst at the desk, and the forward head posture.
Specifically, sleeping on your stomach puts your neck in extension (the opposite of what it does when you are at the computer and on your phone), thereby restoring some order of balance to the system.
Stomach sleeping undoes creep.
It also opens up the airway, encourages nose breathing, and assists with proper oxygenation through exertional diaphragmatic breathing.
What we know about the noctural oxygen saturation is that these levels normal fall as compared to daily oxygen saturation.
Typically, evening oxygenation levels fall by 4–5%.
While this is a normal physiological process, if your saturation levels in the day are already low (due to lack of movement, excessive sitting/computer work, or excess weight) if you have a straight neck, this can further complicate the oxygen game.
Normally we should have a lordosis (or backward curve) in the neck.
This is essential not just for spinal mechanics, but for cerebellar function and the spinal cord that lives inside the spine.
As the world pulls our head forward — into our desks, on our computers, scrolling on Instagram, driving, sitting on the couch at night — this can further reduces our forced vital capacity.
Meaning that if we are inactive during the day, and sleep with a pillow, AND we have developed a straight curve in the neck, the ability to properly take in enough air overnight decreases by another 30%.
Why is this important?
Well for one, it increases the workload on the heart.
If your cells are not getting enough oxygen, we will see things like blood pressure and heart rate begin to elevate as your heart will try to work hard to get necessary oxygen to the entire body.
Think about the ABCs you learned when you took a CPR course. Remember what the A was?
The first thing they do when assessing someone is to open the airway.
Not surprisingly, they achieve this by putting the neck in extension through a head tilt.
They put the neck in extension, and lift the jaw to open the airway.
This is what sleeping on your stomach does — it allows for your neck to be in extension and opens the airway.
(Don’t even get me started with the beds that elevate and bring you into a flexed position).
With back sleeping, your airway is closed off, and it continues to perpetuate the root problem — flexion, flat neck, reduced oxygen capacity.
Stomach sleeping, by definition, is sleeping in extension, with your head rotated to one side.
In other words, the opposite of flexion and being bent over like you typically are during the day.
Because you are on your belly, your diaphragm will also get stronger as this is what is known as exertional breathing.
Meaning, the diaphragm has to work against resistance (your body).
Just like any muscle, the diaphragm needs resistance training in order to grow stronger.
Diaphragmatic breathing is directly related to your ability to expand your thoracic cage, commonly referred to as chest expansion.
You should be able to expand your chest by at least by 2–3 inches in the coronal plane.
What we find with back sleepers, and especially back sleepers with flat degenerating cervical spines, is the accessory muscles of respiration (namely the scalenes, SCM, and upper trapezius) start to work harder and overcompensate for a weakened diaphragm.
This is important because breathing will now happen in the sagittal plane (ie the rib cage will move up and down), rather than the coronal plane (in and out).
Over activation of these muscles (in particular the SCM and scalenes) will cause them to over develop, further straightening the neck, and bringing your neck into flexion.
And we kind of need our rib cages to be able to expand.
Also interesting to note is the diaphragm is innervated by nerves coming out of 3rd, 4th and 5th levels of the neck.
So it is a double win if you can maintain the cure in your neck so as not to damage the phrenic nerve (C3,C4, C5) that feeds the diaphragm.
That, in a nutshell, is my approach to healthy sleeping.
I get that it goes against most things you’ve probably heard.
Chuck the lies you’ve been told about the pillows you “need”, or that you need to stay in one position overnight, or that sleeping on your back is a more “aligned” way to sleep.
Start slowly if you need to, and begin to incorporate the benefits of stomach sleeping into your sleep regimen. Take a minute or two on your belly, with your head turned to one side, and then rotate it to the other.
Notice one side is easier to turn to than the other?
That’s ok. Over time it will get better.
While there is no ONE position that is best all night, there are undeniable benefits to stomach sleeping.
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