Physiological sigh: the quick reset breath, defined

A physiological sigh is two quick inhales through the nose, back to back, followed by one long, slow exhale through the mouth. Stanford researchers tested it in a 2023 randomized trial. Five minutes a day of this pattern lowered breathing rate and lifted mood more than a month of mindfulness meditation did.

How do you do a physiological sigh?

Breathe in through your nose until your lungs feel full. Then, without exhaling, sneak in a second short inhale on top of it. Let it all out slowly through your mouth, as long and complete as feels comfortable. One round can shift how you feel in under 30 seconds.

Some people repeat it for a minute or two when stress is running higher. No equipment, no counting required.

Why does the double inhale matter?

The pattern mirrors a reflex your body already runs on its own. UCLA and Stanford researchers traced spontaneous sighing to two small clusters of neurons in the brainstem. Each firing pops open tiny air sacs in your lungs, called alveoli, that collapse during shallow breathing, keeping oxygen and carbon dioxide exchanging properly. The same research team found this firing happens roughly a dozen times an hour, even when you don’t notice.

Doing the pattern on purpose adds one thing the spontaneous version doesn’t have: an unusually long, slow exhale.

Is the physiological sigh backed by research?

Yes, more solidly than most breathing trends. A 2023 study in Cell Reports Medicine, led by Stanford’s Melis Yilmaz Balban and Andrew Huberman, ran a month-long trial. Participants practiced five minutes daily of either cyclic sighing, box breathing, cyclic hyperventilation, or mindfulness meditation.

Cyclic sighing produced the largest drop in respiratory rate and the biggest gain in positive mood of the four. Benefits appeared after a single session and grew with daily practice.

Is this the same as EMDR or bilateral stimulation?

No, a physiological sigh works through breath alone and isn’t tied to a specific memory. EMDR instead uses bilateral stimulation: alternating left-right eye movements, taps, or tones held alongside a target memory. It’s an approach the American Psychological Association conditionally recommends for PTSD. See EMDR vs meditation, the practice cyclic sighing outperformed in the 2023 trial, for a fuller side-by-side with EMDR.

Some people use a physiological sigh to settle their body before or after a session. EmEase, a self-guided EMDR app, offers guided visual and audio bilateral stimulation at app.emease.com if that mechanism interests you too.

If breathing alone doesn’t take the edge off, steadying your breath walks through a fuller protocol. What to do when breathing exercises don’t work covers what else to try.