by Andrew Proulx MD
Everyone seems to have a preferred sleep position, but does it matter how you sleep? What about that minority of people who prefer to sleep on their stomach (i.e. in the “prone” position)? Is stomach sleeping good or bad for your health? Let’s review the research literature and find out.
What’s the “normal” sleep position?
Studies have shown that children switch positions, sleeping about equally on their front, back, and sides but progressively favor side sleeping as they approach adulthood.1 Among adults, side sleeping is the most commonly preferred position. However, night-time body shifts are also common among adults, with people spending the night in the following positions:2
- Side position 54.1% of the time,
- Back position 37.5%, and
- Front position 7.3%.
Although people move around a lot in their sleep, the predominant sleep positions among adults are:
- Side – 74%,
- Stomach – 16%, and
- Back – 10%.
The preference for side sleeping increases with age, so that the older people get the less they switch positions during sleep and the more time they spend in the side position.1
Why don’t people sleep much in the front position?
There appear to be several reasons why most people show less preference for stomach sleeping:2
- It’s harder to breath in the stomach position – it takes more energy to lift the body to expand the ribcage during breathing,
- The heart has to work harder – the heart’s output is reduced in the stomach position, so the heart must beat faster to compensate, and
- Loss of spine flexibility – as people age they lose spine flexibility, making it harder to adjust to the stomach position.
Can stomach sleeping be harmful?
Some people wake up in the morning with spinal symptoms (such as neck pain, low back pain, or sciatica) that they didn’t have when they went to bed. This has led to the belief that certain sleep postures may provoke spinal symptoms or even injury; stomach sleeping in particular is often implicated. However, clinical investigations have produced conflicting results.
One well-designed study showed that there is no significant relationship between sleep positions (including stomach sleeping) and spinal symptoms.3 However, another study that featured a comprehensive review of sleep studies showed some evidence that side sleeping was protective against waking pain and stiffness in the spine, but the authors concluded that there is not yet enough research evidence to make conclusions.4
Another published comprehensive review of the research literature found no evidence supporting any sleep position over others for spinal health, but found that that more research is needed to make firm conclusions.5 The authors suggested, however, that given the importance of good quality sleep, the most comfortable position may be appropriate, until further evidence proves otherwise.
Obstructive sleep apnea (OAS) is a common, much under-diagnosed breathing condition where the airway is blocked during sleep, causing brief interruptions in breathing throughout the sleep period.6 OSA is a significant issue because it can cause significant daytime sleepiness, and has been associated with increased risk of serious health conditions, including high blood pressure, weight gain, diabetes, cardiovascular disease, and depression.
OSA occurs because the tongue falls back and blocks the airway during sleep. As such, back sleeping is the worst position for OSA. Side sleeping may by the best position for OAS, but stomach sleeping is also better than back sleeping.7 In fact, sleeping on the side or stomach may eliminate OSA in people with mild cases, a technique known as Positional Therapy.8 Although stomach sleeping is better than back sleeping for OSA, left side sleeping has been shown to have the best outcomes.9 Nevertheless, studies have shown that stomach sleeping with a special pillow improve outcomes in individuals with OSA.10
In past times infants were put to sleep on the stomach in the belief that it reduced the risk of choking during sleep. However, in 1992 it was firmly established that putting infants to sleep on their stomach was associated with a higher incidence of sudden infant death syndrome (SIDS).11 This prompted the American Academy of Pediatrics’ “Back to Sleep” campaign, advising parents to put their babies to sleep on their back, and never on their stomach. This measure resulted in a 94% reduction in the incidence of SIDS.11
Stomach sleeping and aging
When the face is pressed into a pillow during sleep, the skin is stretched and folded, forming wrinkles – the “sleep lines” that most people see when they get up in the morning. Over time, these skin distortions during sleep may etch permanent lines in the skin and cause loose, baggy skin, giving the appearance of aging.12 When sleeping on the stomach the face is usually turned to the side and slightly downward, causing more facial contact with the pillow even than when side sleeping. These sleep-related wrinkles tend to appear as vertical lines over the forehead, cheeks, around the eyes, on the chin, and the nasolabial folds (smile lines).
To combat these undesirable effects of stomach sleeping, special pillows are commercially available that are specifically designed to reduce facial skin distortions during sleep.13 These “anti-wrinkle” pillows work by alleviating the pressure on the cheeks, eyes, and mouth during sleep.
Stomach positioning and COVID-19
Putting people with respiratory distress from COVID-19 on their stomach has been shown to substantially increased oxygenation, although the reasons for this are poorly understood.14 Prone (face-down) positioning has been in use for decades for people with respiratory distress, and probably helps by improving the function of the diaphragm, the muscle that is responsible for breathing.15 Unfortunately, these breathing benefits do not seem to apply to healthy prone sleepers.
Tips for stomach sleeping
Stomach sleeping can be mechanically awkward, as people must turn their head to the side to breath, and arm positioning may be awkward. Most individuals who sleep on their stomach sleep with their head to one side and their arms wrapped around or tucked under the pillow. However, pillows specifically for stomach sleepers have been developed and are commercially available, using a variety of designs, including:
- Ultra-thin pillows,
- Wedge pillows,
- Contoured pillows, and
- Adjustable pillows.
Similarly, special mattresses are available with designs that help stomach sleepers get comfortable. These include mattresses with pressure-relief spots placed specifically for stomach sleepers, memory-foam mattresses, and contoured mattresses. For those on a budget, mattress-toppers are also available with designs specific to stomach sleepers.
Although not yet widely commercially available, mattresses known as MPP (mattress and pillow for prone positioning) have been developed. These feature hollowed out areas on the mattress for the arms and head, supported by a T-shaped pillow. These are being investigated specifically for use by individuals with OSA.10
There is anecdotal evidence (i.e. opinion not supported or refuted by research) that by propping up the pelvis with a pillow people can achieve better spinal alignment and reduce the risk of back pain from sleeping on their stomach. Other anecdotal evidence suggests that it is better for spinal health for stomach sleepers to sleep with both legs straight and even, rather than drawing one knee up or crossing one leg over the other, which are common leg positions. This reduces any twisting or contorting of the spine.
Sleeping on the stomach is probably not the healthiest sleep position, and people with certain conditions (such as congestive heart failure) may be advised by their doctor to avoid it. Infants should never be put to sleep on their stomach.
In the absence of any compelling reason to avoid stomach sleeping, those who are most comfortable in that position may benefit from continuing to do so because of the health and wellness benefits of getting a good night’s sleep.
Many of the problems that may arise from stomach sleeping can be avoided or reduced by using a pillow and/or mattress specially designed for prone sleeping, and perhaps by tucking a pillow under the pelvis during sleep.
1. De Koninck, J., Lorrain, D., & Gagnon, P. (1992). Sleep positions and position shifts in five age groups: an ontogenetic picture. Sleep, 15(2), 143–149. Retrieved from https://academic.oup.com/sleep/article/15/2/143/2742862 (click on PDF button at bottom of page for full-text)
2. Skarpsno, E. S., Mork, P. J., Nilsen, T., & Holtermann, A. (2017). Sleep positions and nocturnal body movements based on free-living accelerometer recordings: Association with demographics, lifestyle, and insomnia symptoms. Nature and Science of Sleep, 9, 267–275. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5677378/
3. Cary, D., Collinson, R., Sterling, M., & Briffa, N.K. (2016) Examining the relationship between sleep posture and morning spinal symptoms in the habitual environment using infrared cameras. Journal of Sleep Disorders: Treat and Care, 5(2). Retrieved from https://www.scitechnol.com/peer-review/examining-the-relationship-between-sleep-posture-and-morning-spinal-symptoms-in-the-habitual-environment-using-infrared-cameras-pUfm.php?article_id=4826
4. Cary, D., Briffa, K., & McKenna, L. (2019). Identifying relationships between sleep posture and non-specific spinal symptoms in adults: A scoping review. British Medical Journal, 9(6), e027633. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6609073/
5. Sewell, J.L., Ong, E., Wang, Y., Hussain, S.M., & Cicuttini, F. (2019). What is an optimal spinal position during sleep? A systematic review. Osteoarthritis and Cartilage, 27(1), S459. Retrieved from https://www.oarsijournal.com/article/S1063-4584(19)30543-6/fulltext
6. Van Maanen, J.P., Meester, K.A., Dun, L.N., Koutsourelakis, I., Witte, B.I., Laman, D.M., Hilgevoord, A.A., et al. (2012). The sleep position trainer: A new treatment for positional obstructive sleep apnoea. Sleep Breath. Retrieved from http://www. And sleeping.co.uk/uploads/2/3/1/6/23169594/van_maanen_2012.pdf
7. Howley, E.K., Fotinakes, P.A., & Tsai, S. (2020). 4 best sleeping positions to improve sleep apnea. US News Health. Retrieved from https://health.usnews.com/conditions/sleep-apnea/articles/best-sleeping-positions-for-sleep-apnea
8. Ravesloot, M. J., van Maanen, J. P., Dun, L., & de Vries, N. (2013). The undervalued potential of positional therapy in position-dependent snoring and obstructive sleep apnea-a review of the literature. Sleep & Breathing , 17(1), 39–49. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3575552/
9. Oksenberg, A., & Gadoth, N. (2016). Breathe well, sleep well: Avoid the supine and adopt the lateral posture. Sleep Health, 2(2), 90-93. Available from academic sources; abstract retrieved from https://www.sleephealthjournal.org/article/S2352-7218(16)00032-2/abstract
10. Bidarian-Moniri, A., Nilsson, M., Attia, J., & Ejnell, H. (2015). Mattress and pillow for prone positioning for treatment of obstructive sleep apnoea. Acta Oto-laryngologica, 135(3), 271–276. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4389730/
11. Jones M. W. (2004). Supine and prone infant positioning: A winning combination. The Journal of Perinatal Education, 13(1), 10–20. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1595182/
12. Anson, G., Kane, M.A., & Lambros, V. (2016). Sleep wrinkles: Facial aging and facial distortion during sleep. Aesthetic Surgery Journal, 36(8), 931–940. Retrieved from https://academic.oup.com/asj/article/36/8/931/2613967
13. Poljsak, B. , Godic, A. , Starc, A., & Dahmane, R. (2016). The neglected importance of sleep on the formation and aggravation of facial wrinkles and their prevention. Journal of Cosmetics, Dermatological Sciences and Applications, 6, 96-99. Retrieved from https://www.scirp.org/journal/paperinformation.aspx?paperid=67035
14. Mittermaiera, M., Pickerodt, P., Kurtha, F., Bosquillon de Jarcya, L., Uhriga, A., Garciaa, C., et al. (2020). Evaluation of PEEP and prone positioning in early COVID-19 ARDS. EClinicalMedicine, 28, 100579. Retrieved from https://www.thelancet.com/pdfs/journals/eclinm/PIIS2589-5370(20)30323-0.pdf
15. Venus, K., Munshi, L., & Fralick, M. (2020). Prone positioning for patients with hypoxic respiratory failure related to COVID-19. Canadian Medical Association Journal, 192(47), E1532-E1537. Retrieved from https://www.cmaj.ca/content/192/47/E1532