Sleep Position and Snoring: Does Side-Sleeping Really Work?

Yes — for a large group of snorers, simply not sleeping on your back is one of the most effective free changes available. When researchers pooled the available studies in 2024, they found snoring was longest and most severe in people sleeping on their backs, and least severe when sleeping on their sides.^[1]

The catch is staying off your back for a whole night, every night, while unconscious. That’s what positional therapy is about — a family of techniques from the folk-remedy tennis ball to modern vibrating trainers — and the evidence on what works, and what people actually stick with, is surprisingly rich.

Why sleeping on your back makes snoring worse

Snoring is the sound of air vibrating past relaxed tissue in a narrowed airway. Lie on your back and you give gravity the best possible angle: the tongue and soft palate fall backwards towards the throat, narrowing the passage and speeding up the airflow that makes tissue flutter.^[2] Back-sleeping appears on Mayo Clinic’s list of snoring risk factors for exactly this reason,^[3] and the NHS’s core self-help advice for snorers is to sleep on your side.^[4]

Roll onto your side and the tongue falls sideways rather than backwards, leaving the airway clearer. For the mechanics in full, see what causes snoring.

Are you a positional snorer?

Some people snore in every position; others snore mainly or only on their back. The second group — “positional snorers” — are the ones who benefit most. Research in positional obstructive sleep apnoea shows that position modification is genuinely efficacious for people whose breathing problems concentrate in supine (back) sleep.^[5]

How do you know which you are? Ask whoever shares your room whether the noise stops when you roll over, or use one of the many phone apps that record snoring through the night and let you compare it against how you woke up. If you snore just as loudly on your side, position isn’t your main problem — look at nasal issues, weight or the other causes in our complete guide.

The tennis-ball technique Moderate evidence

The classic method: something firm attached to your back so that rolling over becomes uncomfortable and you turn back onto your side without waking. In the version used in studies, a tennis ball is held in a pocket sewn onto the back of a pyjama top or T-shirt.

Does it work? Yes and no. Research shows the technique does reduce time spent sleeping on the back, though it’s less effective than CPAP for sleep apnoea — and its real weakness is that long-term adherence is poor.^[6] People find it uncomfortable, start sleeping without the shirt, and drift back to old habits. Follow-up studies of positional devices at home confirm that usage and effectiveness decline over time,^[7] with one six-month study documenting the same drop-off.^[8]

Verdict: a legitimate, evidence-backed, nearly-free starting point — as long as you’re honest with yourself about whether you’re still using it a month in.

Vibrating position trainers Moderate evidence

The modern answer to the tennis ball is a small sensor, worn on the chest or neck, that detects when you roll onto your back and vibrates gently until you move — training you off your back without the discomfort.

In a 2015 trial published in the Journal of Clinical Sleep Medicine, a vibrating Sleep Position Trainer matched the tennis-ball technique on the apnoea-hypopnoea index, but with better comfort and better compliance.^[9] Further trial data on positional therapy devices have been published in Scientific Reports.^[10] Since adherence is precisely where the tennis ball fails, that comfort advantage matters more than it sounds.

These trainers have the best evidence of any position-related gadget. The same cannot be said of “smart pillows” — see below.

Pillows and raising the head of the bed

You don’t have to change position to change geometry. A 2024 systematic review in the Journal of Personalized Medicine — nine studies, 235 patients — looked at both body position and head-of-bed elevation. Alongside confirming that supine sleep produced the longest and most severe snoring and lateral (side) sleep the least, it found that elevating the head of the bed by 30 degrees reduced snoring time from 17.3% to 12.5% of the night, and that even a 7.5-degree tilt produced roughly a 7% relative reduction.^[1]

Elevation works with gravity instead of against it: a raised head position helps keep the airway open even before you factor in side-sleeping.

A practical how-to

• Sew the pocket. For the studied tennis-ball technique: stitch a pocket (or half a sock) to the centre-back of a snug T-shirt and pop a tennis ball in before bed.
• Try a positional pillow or a body pillow. The NHS suggests a special pillow among its side-sleeping aids;^[4] a long body pillow hugged in front of you also makes rolling flat less likely, and a firm pillow wedged behind your back blocks the roll altogether.
• Use a bed wedge — or raise the bed itself. The NHS also lists a bed wedge as an option.^[4] A foam wedge under the mattress head, or sturdy risers under the head-end legs, achieves the elevation the studies measured. A tall stack of soft pillows is the worst way to do it, as your head tends to slide off and your neck can kink forward.
• Consider a vibrating trainer if the free methods lapse. They cost more, but the compliance data are on their side.^[9]

What about smart pillows?

App-connected pillows that claim to detect snoring and adjust your head position are heavily marketed, but there are no quality randomised trials behind consumer smart pillows — the evidence is simply insufficient to recommend them. If you want technology with data behind it, the vibrating position trainer is the one that has actually been tested against an established technique.^[9]

The adherence problem — and an honest expectation

Every positional method shares one weakness: it only works on the nights you use it. Studies consistently show usage declining over months,^[7][8] so build the habit deliberately — keep the shirt or trainer where you’ll see it at bedtime, and ask your partner to tell you (kindly) when the snoring returns. Our partner’s guide has more on making this a joint project.

The bottom line

If your snoring is worst on your back, positional therapy is among the best-value fixes in existence: side-sleeping is NHS-endorsed, the tennis ball is nearly free and genuinely studied, head-of-bed elevation adds a measurable further reduction, and vibrating trainers solve the comfort problem for those who can spend a little. Pair it with the lifestyle changes that shrink the underlying problem, and see the complete guide for how position fits into the bigger picture.