What cyclic sighing actually is
Cyclic sighing is two inhales through the nose — one comfortable breath, then a short second sip of air on top of it — followed by one long, unhurried exhale through the mouth. You repeat that shape for a few minutes. That is the entire technique. If you have seen it written as double inhale, long exhale, or as the physiological sigh, that is the same breath under a different name.
The pattern is borrowed from something your body already does without asking you. Several times an hour your breathing slips in a breath that is bigger than the rest, often with a small catch at the top, and then empties in one long release. Physiologists call it a sigh. You notice it most after you have been sitting still for a long stretch, or in the moment a worry resolves and your chest lets go all at once.
Cyclic sighing takes that involuntary shape and makes it deliberate. Rather than waiting for a sigh to arrive, you produce one, then another, then another, at a pace you choose. The timer above runs the shape used in the Stanford trial described further down — a comfortable nasal inhale, a shorter second one on top of it, then a long exhale through the mouth — on fixed counts of roughly two seconds, one second and six seconds. The trial gave its participants that shape rather than a stopwatch, so treat the counts as this timer’s pacing choice and not as the studied protocol. They make a nine-second cycle, or about seven breaths a minute, roughly half the pace of ordinary resting breathing in an adult.
Two things make it unusual among breathing exercises. The first is that there is no breath-hold anywhere in it, so nothing in the pattern can feel like being unable to breathe. The second is that the exhale ends up twice as long as the two inhales put together, without you having to hold four different numbers in your head. The circle counts; you follow it.
How to do it
Read this once, then start the timer and stop reading. The visual and the audio cue will carry the rhythm for you.
1. Settle, and let your mouth be free
Sit or lie down wherever you are. You do not need a straight back or a special posture. The only thing that matters is that your mouth can open, because the exhale leaves that way and it should not be muffled.
2. Breathe in through your nose until you are about full
Take a normal, comfortable inhale through the nose. Fill up to roughly three quarters, not to the absolute top. About two seconds is right. If you fill completely here you will have nowhere to put the second breath.
3. Add a short second sip on top
Without letting any air out, take a quick extra inhale through the nose. It is short, about one second, and it feels like a small catch at the top of your chest. This second breath is the part that makes this cyclic sighing rather than ordinary deep breathing.
4. Let the exhale go slowly through your mouth
Open your mouth and let the air leave in one long, unhurried stream, as though you were fogging a window very slowly. Around six seconds. Do not push the last of it out. When it runs out on its own, the breath is finished.
5. Begin the next breath without a pause
There is no hold anywhere in this pattern. As soon as the exhale finishes, start the next nasal inhale. The rhythm should feel continuous, like a wave, not like a series of separate instructions.
6. Keep going for about five minutes
One cycle takes about nine seconds, so five minutes is roughly thirty-three breaths. Most people notice the exhale getting longer and quieter on its own after the first minute. Let that happen rather than forcing it.
Why the second inhale is there
The short top-up is the part people skip, and it is the part that makes the technique distinct. It is easy to treat cyclic sighing as "one big breath in, one long breath out" and lose the double, especially once you stop watching the circle.
The reason it is in the pattern is that a natural sigh has the same double shape. Li and colleagues traced the brainstem circuit that produces sighs in rodents and published it in Nature in 2016, and their description of the breath itself is precise: "Occasionally, a second preBötC burst immediately follows the first, and this 'double burst' leads to the augmented inspiration of a sigh, typically about twice the volume of a normal breath." The same paper says the recurrence of sighs during ordinary breathing "enhances gas exchange and may preserve lung integrity by reinflating collapsed alveoli", and puts the spontaneous rate at "several per hour in humans". That is rodent work on the mechanism of sighing, not a study of this exercise in people, and it does not show that copying the shape on purpose produces any particular feeling. It is here only to explain where the double inhale comes from.
What the second inhale reliably does for you is more mundane and more useful: it gives you a clear physical marker at the top of every breath. You cannot do it absent-mindedly. When your attention drifts — and it will — the missing catch at the top is what tells you, without any self-criticism required, that you drifted.
When to use it, and when not to
Cyclic sighing suits a particular kind of moment: keyed up, short on time, unwilling to sit through anything that feels like meditation. Five minutes between meetings. The car park before you go in. The gap after a difficult phone call, when your hands are still unsteady. It is also a reasonable thing to do lying in bed, though for sleep specifically many people prefer a longer, quieter wind-down that does not involve breathing out through the mouth beside a sleeping partner.
It suits people who bounce off other patterns. If box breathing's holds make you feel trapped, or if 4-7-8's seven-count leaves you gasping at the eight, this asks nothing of you but a long out-breath. Nothing is held. Nothing has to be counted.
It is a poor fit for a few situations. It is not a concentration exercise — if you want something to steady your attention for a long stretch of work, an even in-and-out rhythm suits that better. It is not something to do while driving, cycling or operating anything, because deliberately slowing your breathing can make you lightheaded and because your eyes belong on the road. And it is not a treatment. If breathlessness, chest pain, or a racing heart are new, or getting worse, or waking you up, that is a reason to see a doctor rather than a reason to breathe differently.
Who should take this slowly
Cyclic sighing contains no breath-holds and no fast breathing, which makes it one of the gentler patterns on this site. It is still not weightless, and a few people should ease into it or check first.
- If you are pregnant. Slow, hold-free breathing is generally comfortable in pregnancy, but ask your midwife or doctor before taking up any new breathing practice, and stop if it makes you dizzy.
- If you have a heart condition, uncontrolled high blood pressure, or a respiratory condition such as asthma or COPD. Deliberately changing your breathing rate can feel different from what you are used to. Check with the clinician who knows your case, and never use a breathing exercise in place of an inhaler or prescribed medication.
- If you have epilepsy. Any change in breathing pattern is worth raising with your neurologist first.
- If you have had recent surgery, particularly chest or abdominal. A deep double inhale can pull on healing tissue. Wait until you have been cleared.
- If controlled breathing has triggered panic or dissociation for you before. Some people find that watching the breath is itself the trigger. Open your eyes, look at something in the room, and use a grounding exercise instead. That is a sensible choice, not a failure.
- Anyone, on the day. Dizziness, tingling in the hands or lips, or a tightening chest all mean stop, breathe normally, and let it settle before you try again with smaller inhales.
What the evidence shows
There is one good trial behind this pattern, and it is worth knowing exactly what it did and did not find. Balban and colleagues at Stanford ran a remote randomized controlled study, published in Cell Reports Medicine in January 2023 and indexed on PubMed as 36630953. The abstract states the design plainly: "Here, we report a remote, randomized, controlled study (NCT05304000) of three different daily 5-min breathwork exercises compared with an equivalent period of mindfulness meditation over 1 month." The three exercises were cyclic sighing, box breathing, and cyclic hyperventilation with retention. The abstract states the primary result this way: "we show that breathwork, especially the exhale-focused cyclic sighing, produces greater improvement in mood (p < 0.05) and reduction in respiratory rate (p < 0.05) compared with mindfulness meditation." It then closes on a deliberately modest note: "Daily 5-min cyclic sighing has promise as an effective stress management exercise." The full text is open access if you want the detail.
The honest limitations matter as much as the result, and the authors state them themselves. One hundred and eight people enrolled: twenty-four were randomized into the mindfulness meditation control condition and eighty-four across the three breathing conditions, which leaves each individual breathing group small. In the paper's words, "sample size in each group was relatively small, limiting the statistical power to compare individual breathwork groups with each other." Mood and anxiety were self-reported — participants filled in the State Anxiety Inventory and the Positive and Negative Affect Schedule before and after each day's five minutes — and self-report is exactly the kind of measure that moves when you believe an exercise is helping. Nobody was in the room either: "The remote nature of the study limited the monitoring of how closely participants followed the instructions on a daily basis." The physiological side rests on firmer ground, because respiratory rate, heart rate and heart rate variability came off a WHOOP strap mailed to each participant rather than off a questionnaire.
So: one month, a hundred and eight people, a real active control rather than a waiting list, and a modest, clearly stated effect. That is more than most breathing exercises can claim, and much less than a treatment. It does not show that cyclic sighing treats anxiety, depression or any other condition, and no one should stop or change medical care on the strength of it. One trial is a beginning, not a settled question — a larger study could easily narrow the gap between cyclic sighing and the other three practices. If you want the rest of the picture, including where the evidence for other patterns is thinner, read what the research says.
Common questions
How long should a cyclic sighing session be?
Five minutes is the length used in the Stanford trial, and it is the default on this timer. If five feels long, two or three minutes is a real session and not a failed one. There is no evidence that longer is better, and nothing to gain from pushing past the point where it stops being pleasant.
Do I have to exhale through my mouth?
Nose in, mouth out is the version the Stanford trial described, and a mouth exhale is easier to slow down and to hear, which helps you pace yourself. The same instructions told participants they were welcome to do the breathing entirely through the nose if they preferred, so a slow nasal exhale is a fair substitute when you would rather not make a sound. Keep the double inhale either way.
Is cyclic sighing the same thing as the physiological sigh?
A physiological sigh is the single double-inhale-then-long-exhale breath your body already produces on its own several times an hour. Cyclic sighing is what you get when you do that breath deliberately, one after another, for a few minutes. Same shape, repeated on purpose.
Can I use cyclic sighing during a panic attack?
Many people find long-exhale patterns easier to tolerate in a panic attack than patterns with breath-holds, because nothing in them feels like being unable to breathe. If it helps, use it. If trying to control your breathing makes the panic worse, stop and use grounding through your senses instead. Panic attacks that keep happening deserve a conversation with a clinician, not just a timer.
How is cyclic sighing different from box breathing or 4-7-8?
Box breathing and 4-7-8 both contain breath-holds and both ask you to keep count. Cyclic sighing has no hold at all and only one number that matters, the long exhale. That makes it usable when you are too agitated to count, and it is why it tends to be the easier of the three to start with.
Why do I feel lightheaded when I do this?
Almost always because the inhales are too big. Cyclic sighing is not meant to move a lot of air; the first breath should be comfortable rather than maximal and the second is only a sip. Make both smaller, keep the exhale long, and the lightheadedness usually disappears. If it does not, stop and breathe normally.
Related
A note on what this is
Help Me Breathe is a breathing timer written by one person, not a clinic. Nothing on this page is medical care, none of it diagnoses anything, and none of it replaces treatment or medication. If something about your breathing, your heart or your mood worries you, please talk to a doctor. Read the full medical disclaimer.