The physiological sigh: how to do it and when it helps

The physiological sigh is two breaths in through the nose, one straight after the other, followed by one long, slow breath out through the mouth. One takes well under ten seconds, and one to three in a row is a quick way to settle yourself when a moment at work has you wound up.

You already know the movement, because your body does it on its own. Doing it on purpose is a small, useful tool. It is not a treatment, and the end of this page is about the difference.

How to do a physiological sigh

You can do this sitting at your desk, eyes open, while a call connects.

1. Breathe in through your nose. A normal, fairly full breath, not a huge gulp.
2. Take a second, shorter sip of air through your nose on top of the first, as if topping off your lungs. It is a small breath, and it may feel a little odd the first time.
3. Breathe out slowly through your mouth until your lungs feel empty. Let the out-breath take longer than both in-breaths together. Loose lips, like a quiet sigh, is fine.
4. Breathe normally for a moment, then repeat once or twice if you want to.

Some people find the second inhale hard to fit in at first, because their lungs already feel full. Make the first breath a little smaller, so there is room for the top-up. If your nose is blocked, breathe in through your mouth instead. The long, slow exhale is the part not to skip.

Why two breaths in and one long breath out?

Everyone sighs without noticing, every few minutes, and research suggests people sigh more often under stress. The deliberate version copies that reflex. The usual explanation for its shape goes like this.

Your lungs are made of hundreds of millions of tiny air sacs called alveoli. During shallow breathing, the kind people slip into when they are hunched over a keyboard and concentrating, some of those sacs partly deflate. The second, shorter inhale helps reopen them. With more of the lung open, the long exhale clears carbon dioxide more effectively, and rising carbon dioxide, more than falling oxygen, is what drives the feeling of needing air.

The exhale matters for a second reason. Your heart speeds up slightly each time you breathe in and slows slightly each time you breathe out. That rhythm is normal and well documented. An out-breath that is longer than the in-breath leans on the slowing half, which is one reason so many calming breathing patterns, not only this one, stretch out the exhale.

Treat this as the common explanation rather than settled fact. The physiology is real, but how much each piece contributes to feeling calmer is still being studied.

What did the Stanford research find?

Two pieces of research come up whenever the physiological sigh is mentioned, and they are about different things.

The first, published in Nature in 2016 by a team from Stanford and UCLA, was about the automatic sigh. Working in mice, the researchers identified a small group of nerve cells in the brainstem that turns ordinary breaths into sighs. It explained where the reflex comes from. It was not a study of sighing on purpose to feel better.

The second is the one most people mean. In 2023, a Stanford team that included the psychiatrist David Spiegel and the neuroscientist Andrew Huberman published a study in Cell Reports Medicine. Volunteers spent five minutes a day for a month on one of four practices: cyclic sighing (physiological sighs repeated for the whole five minutes), box breathing, a faster pattern with breath holds, or mindfulness meditation. According to the authors, the breathing groups reported a bigger lift in mood than the meditation group, and cyclic sighing showed the largest effect of the four.

That is encouraging, and it is also one study. It was run remotely, with volunteers who chose to take part, and mood was self-reported. It suggests that a few minutes of exhale-heavy breathing a day can help people feel better. It does not show that sighing fixes stress, anxiety or anything medical.

How many sighs, and how often?

People use the technique in two ways, and they suit different moments.

For a quick reset, many people find one or two enough. If three haven't helped, more of the same rarely does, and a short walk or a glass of water may do more. For the longer practice, five minutes is what the study used. There is nothing magic about the number, but it is long enough to settle into and short enough to keep doing.

If you already practice box breathing, there is no need to choose. The sigh is quicker and needs no counting, which makes it easier in the middle of a busy afternoon. The box suits a calmer minute, when you want the counting to give your mind something to do.

How to use it between meetings

Meeting days are where the sigh earns its place. You can't leave the room in the middle of a call, but you can take two sighs before you unmute to answer a hard question, and nobody will see more than a slightly long breath.

The gaps between calls matter more. When meetings run back to back, the tension from one carries straight into the next. A couple of sighs at the end of each call, before you open the next link, draw a line between them. If your calendar barely has gaps, adding buffers between meetings helps make room for one.

The catch is the same as with every breathing habit: you remember it on calm days and forget it on busy ones. A cue from outside your own head helps. Notchpals has one in its Self-care area, the Breathe moment, which turns up once you have worked for about ninety minutes without a real break. With Kapi the capybara in your crew, it sounds like this:

KapiBreathe in like you're smelling an orange. Out slow. Three times. Mmm.

Make each of those breaths a sigh, with a second sniff on top of the first, then press Done. A Schedule character can give you a second cue on meeting days, if you have allowed Notchpals to see when your meetings start. It comes a few minutes before each one, which is just enough time for two sighs before you click the link.

WalterStarts soon. You'll be fine. Probably. Hmph. Go on.

When is a breathing exercise not enough?

The sigh helps with the everyday tension of a working day. It doesn't treat panic attacks, anxiety disorders, depression or burnout. If worry or low mood has hung around for weeks, or is getting into your sleep, your work or your evenings, see your doctor or a therapist. Breathing can sit alongside that help. It can't stand in for it.

Some practical cautions:

• Feeling dizzy or lightheaded means stop. Breathe normally until it passes. You probably breathed in too hard or did too many sighs back to back.
• Check with a doctor first if a heart or lung condition affects your breathing, or if breathing exercises tend to leave you short of breath.
• Chest pain or sudden breathlessness is not stress to breathe through. Get medical help.
• If watching your breath makes you more anxious, which happens to some people, skip it and take a short walk instead.

The best time to learn the sigh is on an ordinary afternoon. Do one now: a breath in, a short top-up, a long breath out. By the time a hard meeting comes along, your body will already know the shape of it.