Physiological Sigh Before Bed: The Double Inhale and Long Exhale
A physiological sigh is a slow breath in through the nose, a shorter second breath to top up, then one long, slow exhale. Used before bed, it is a calm-down tool rather than a sleep switch, because the study that tested it found no change in sleep.
At a glance
- Time: about five minutes, once a day, which is the length the study used.
- Position: sitting, or lying down if that is more comfortable.
- Pattern: two inhales through the nose, then one slow exhale through the mouth.
- Best moment: a racing mind before the lights go out.
- Skip it: if you feel dizzy, or if you have asthma or another breathing or heart condition and your doctor has not said it is fine.
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What is a physiological sigh, exactly?
It is a breathing pattern with two inhales and one long exhale, and the version tested in the 2023 study had a slow first inhale, a second inhale that was shorter and smaller, and an exhale that went out slowly and fully, with both inhales ideally through the nose and the exhale ideally through the mouth. Slow first. Shorter second. Long and full on the way out.
If you have ever taken a deep breath to let out tension, you already know the feel of a long exhale, and the routine simply asks you to do it on purpose, on a schedule, with the inhales arranged in a set pattern. The study gave no breath holds, so do not add one, because adding a hold would turn the study’s pattern into a different exercise altogether. Keep the breathing gentle and relaxed. A breathing pattern disorder leaflet from Worcestershire Acute Hospitals NHS Trust describes the same idea: gentle breaths taken in and out through the nose, from the lower chest and stomach rather than the upper chest.
How do you do one, step by step?
- Sit or lie down somewhere quiet, with the lights low and your phone out of reach.
- Breathe normally for a few breaths, and let your shoulders drop.
- Take a slow inhale through the nose, letting your belly rise first.
- Take a second, shorter inhale through the nose to top up your lungs.
- Breathe out slowly and fully through the mouth, softening your jaw and shoulders as the air leaves.
- Repeat for five minutes, the length the study used, then go back to normal breathing.
Nose in. Mouth out. Keep it slow. Do not rush the exhale. Let it take as long as it takes.
What did the 2023 study actually measure?
The study was published in Cell Reports Medicine in January 2023. Balban and colleagues ran it over 28 days, with one five-minute session a day. A little over a hundred adults took part. They were split across cyclic sighing, box breathing, a cyclic hyperventilation routine with breath holds, and a mindfulness meditation control.
Here is what the paper reports. Positive mood rose more in the cyclic sighing group than in the meditation group, and breathing rate fell by more. State anxiety did not differ between sighing and meditation. Heart rate and heart rate variability did not change significantly. Sleep, tracked with a wearable device, showed no significant change.
What the study can tell you is that a short daily routine changed how people rated their mood and how fast they breathed over a month, compared with a meditation routine of the same length, but it cannot tell you whether the same change will show up on a bad night, in a noisy home, or for someone with a breathing condition. Two cautions apply. The paper reports averages and p values rather than one headline percentage, so ignore any site that quotes a single number as the result. This is one trial, so treat it as promising rather than proven.
Sighing lifted mood more than meditation in this trial, but it did not change sleep.
How do you know if it suits you?
Keep it simple. Before your first session, rate how calm you feel from 1 (wired) to 5 (settled). Do the sigh at the same time each night for a week, then rate yourself again at the same time, and note whether falling asleep felt quicker, slower or the same. Write it down. Memory is unreliable here, because one good night can look like a trend and one bad night can look like a failure.
If the numbers do not move, that is useful information too, because it tells you the sigh is not the right tool for your nights, and that is a finding worth acting on rather than forcing the routine for another month out of loyalty. Try the box breathing or 4-7-8 routines linked below instead, and pick the one that leaves you feeling steadier by the end of the week.
When should you skip it, or stop?
Stop if you feel dizzy or light-headed, and go back to normal breathing through the nose, because a breathing routine is meant to settle you rather than test how much air you can take. The NHS trust leaflet says that if symptoms worsen, you should call your GP, 111 or 999, so do not push through them.
Check with your doctor first if you have asthma, a lung or heart condition, or any other breathing problem. Never hold your breath to make the pattern longer, and never force an inhale. If you feel faint, or if breathing symptoms get worse rather than settle, call your GP or 111, or call 999 in an emergency.
Insider tip: keep it gentle
Let your jaw and shoulders drop on the long exhale, and keep the inhales soft rather than big. Dim the room, put your phone face down, and do one five-minute session, which is what the study used. Doing it at the same time each night turns it into a habit rather than a test.
If the sigh is not enough and your mind keeps racing, the 4-7-8 breathing guide has its own count, and box breathing and grounding covers a different pattern for tense moments. For a full wind-down, see our home remedies and calm routine, and for restless nights the bechaini guide walks through a short method. More breathing and wind-down guides are in the Sleep & Relaxation hub.
Breathing before bed: your questions answered
Does the physiological sigh help you fall asleep faster?
The 2023 study did not show that. Sleep measures showed no significant change, so use the sigh as a way to settle before bed, not as a guaranteed sleep fix.
How do you do a physiological sigh?
Breathe in slowly through the nose, take a shorter second inhale through the nose, then breathe out slowly and fully through the mouth. Repeat for five minutes, the length the study used.
How long should I do a physiological sigh for?
The study used five minutes once a day over 28 days. Shorter sessions were not tested, so any shorter routine is your own choice rather than the trial’s result.
Is cyclic sighing the same as the physiological sigh?
The study called the pattern cyclic sighing. It has the same double inhale and long exhale this guide describes, so the two names point to the same breath.
Should I hold my breath during the sigh?
No. The study protocol has no breath holds, so do not add one. Stop and return to normal breathing if you feel dizzy.
Does sighing breathing help with stress?
In the trial, mood rose more than with meditation and breathing rate fell more, but state anxiety did not differ from meditation. That makes it a promising calm-down tool, not proof that it works for everyone.
What if I feel dizzy when I breathe deeply?
Stop, sit or lie down, and return to normal breathing through the nose. If dizziness keeps happening or you feel unwell, see your GP, and call 999 in an emergency.
Is the physiological sigh safe for everyone?
The study did not test every health condition, so check with your doctor first if you have asthma, a heart condition or another breathing problem.
Can I use the sigh and the 4-7-8 breath together?
You can use one after the other to settle, but keep both gentle and follow the count in the 4-7-8 guide rather than a faster version of it.