I’ve spent years exploring and experimenting with various sleep positions, and in this guide, we’re going to break the pros and cons of each in ways you’ve never seen before!
So let’s get right into it!
Most people sleep on their sides, odds are that you probably do!
I believe that this position is most popular due to the body’s subconscious preference for a fetal-like state during relaxation.
And of course, that’s what it is for most, we don’t call it the fetal position for nothing.
While the degrees vary, the arms, legs, and hips are usually slightly bent. This is not only comforting mentally but also physically.
Advantages of Side Sleeping
1. You Can Get Fully Relaxed
It’s likely this position is preferred by many due to the possibility of bending the hips and knees, allowing for full relaxation of the sacroiliac muscles (the ones in your pelvis) as well as the lumbar spine.
2. Neutral Spine
Another benefit to side sleeping, at least over stomach sleeping, is that it’s possible to align the spine neutrally, which is what we want at night.
Whether or not you can achieve a neutral spine on your side will depend entirely on your bed, the size of your hips and shoulders, and your weight.
3. Better Breathing
Some people can suffer from breathing problems like obstructive sleep apnea while sleeping on their backs. While there are many solutions to these problems, side sleeping is definitely one of them!
Sleeping on your side can take the weight of gravity off your esophagus and prevent the collapse of the throat.
Disadvantages of Side Sleeping
There are unfortunately many potential downsides to the side sleeping position that you should be aware of.
1. Facial Deformation and Aging
Both side and stomach sleeping positions exert pressure and shear forces on facial structures.
In fact in this study, researchers filled up a PVC pillow with air and took photos of facial features during and after using the pillow.
As you can imagine, 8 hours of facial compression, shear, and tension can lead to wrinkles over a lifetime.
Whether or not this is worth considering is up to you of course.
2. Appendage Numbness and Circulation
It’s quite easy to pinch a nerve or blood vessel while sleeping on your side and loss of circulation and numbness in the extremities is common in side sleepers.
This can limit blood flow and the excretion of metabolic waste in these areas and leads to inevitable tossing and turning all night long.
In fact, it has been shown that carpal tunnel syndrome is associated with side sleeping.
3. Tossing and Turning
Side sleepers will toss and turn throughout the night as the body attempts to compensate for the excessive compression of tissues and loss of circulation.
This of course interrupts sleep processes that can only occur when the body’s motor functions have been shut down, such as REM.
4. Head Congestion
Assuming you’re sleeping on a flat surface, whatever side you choose will get congested overnight. Many people with sinus issues and allergies will know this, as they will wake up with one side of the body affected more than the other. [R] [R] [R]
5. Non-neutral Spine Curvature
The fetal position can cause the spine to be curved into a non-neutral position, possibly reducing the adequate rehydration of intervertebral areas and contributing to back pain and tossing and turning.
6. Abdominal Compression
Trunk flexion can increase intra-abdominal pressure, which can limit diaphragm expansion and negatively impact breathing fullness.
7. Breast Compression
Sleeping on your side will compress the lower breast tissue as well as the lymph nodes near the armpit.
This limits blood flow and metabolic waste removal for that area, and over time may help contribute to breast tumors and cancer in the same way that wearing a tight bra will.
If you have particularly large breasts this may be of more concern.
The supine sleep position is the second most common sleep position and is far more common in Asian countries than in Western countries.
This could be due to a difference in the lumbar curvature in these respective populations. [R]
There are various benefits to sleeping in this position if you can get it to work for you.
Advantages of Back Sleeping
Back sleeping is generally considered the most advantageous position for several reasons.
1. Maintaining a Neutral Spine
It’s much easier to maintain a proper neutral spine posture while sleeping on your back.
This does depend on your mattress, as a mattress too stiff for your body will cause pressure spots in the shoulder and tailbone area leading to discomfort and circulation issues in that area.
It’s much easier to maintain a neutral spine with an adjustable bed base.
2. Less Movement Disruption
Movement, and thus sleep interruption, is lowest in this position due to more weight being distributed across a larger surface area.
There is less pressure weighing down on one small area so it’s less likely you’ll need to move in order to alleviate circulation issues.
3. Minimal Organ Compression and Impingement
Back sleeping keeps organs from pressing upon one another and keeps the heavy back off of the organs, unlike stomach sleeping.
4. Optimal Breathing and Blood Flow
For those who don’t suffer from disordered breathing, of course, sleeping on your back can help with breathing ease as there is less chance of compressing the lungs.
There’s also less neck compression in this position which can improve circulation to and from the brain.
Disadvantages of Back Sleeping
Now there are disadvantages as well.
1. Breathing Difficulties
Breathing difficulties are most common in this position due to gravity narrowing the esophagus at night.
Back sleeping gets a bad rap from sleep apnea associations. It’s true that back sleeping on a flat surface can promote sleep apnea, although this isn’t the case for everyone.
I suggest raising the torso by ~30° to eliminate this issue.
2. Lumbar Discomfort
Depending on your ethnicity (Asians seem to have less lumbar curvature) laying flat on your back can cause a pressure spike in the lumbar area.
This can be alleviated by raising the leg area which is done in the zero gravity position.
3. Iliopsoas Discomfort
Again, a curved lumbar area means your iliopsoas muscles in your hips won’t feel fully relaxed unless your hips and knees can be bent, hence the preference for lateral positioning in most people.
Raising the legs slightly can be very comforting, as it takes some of the tension out of these muscles.
4. Ulnar Nerve Impingement
By laying on your back and placing your hands and arms across your abdomen, you run the risk of compressing the ulnar nerve.
This can be mitigated by inclining the torso (less pressure), keeping your arms at your sides, and/or placing pillows at your sides to distribute pressure more evenly across the elbow area.
Ah, stomach sleepers, the oddballs.
I don’t have many good things to say about this position…
It’s the least common of the big three and for good reason, there are a lot of downsides and very little upsides.
Advantages of Stomach Sleeping
I really haven’t come across any benefits to sleeping on your stomach… sorry, I suppose if you seem to sleep well in this position that’s an advantage! But there are so many downsides I’d consider transitioning away from it.
Disadvantages of Stomach Sleeping
1. Breast Compression
Even more than side sleeping, stomach sleeping can of course compress breast tissue, limiting blood flow and waste removal.
I just can’t recommend this position, especially for females.
2. Shallow Breathing
The rib cage is meant to expand outwards as we breathe, stomach sleepers will have trouble breathing fully or deeply throughout the night.
3. Internal Organ Compression
Stomach sleeping means that the internal organs must bear the weight of the back which is composed of mostly bone and muscle, meaning it’s quite heavy. This could result in reduced blood flow throughout the abdominal cavity.
4. Nostril Compression
This position can result in partial compression of the nostrils, again producing shallow breathing.
5. Neck Artery Compression
Stomach sleeping requires the neck to be turned 90 degrees, which can compress the vertebral arteries and veins leading to and from the brain, as occurs with SIDS.
6. Facial Compression
Facial compression will be greater for stomach sleepers than for side sleepers. Side effects of this may be a bent nose, puffy eyes, wrinkles, and sinus congestion.
7. More Frequent Urination
Since the bladder is located near the front of the abdomen and stomach sleeping puts more pressure on the bladder, it will feel fuller, sooner, resulting in more frequent bathroom trips and interrupted sleep.
The Best Sleep Position
In my humble opinion, the zero gravity position is the king of all sleeping positions!
If you’re curious to learn more about it and how to implement it, we go over all of the pros and cons here.