Cyclic Sighing: The 5-Minute Breathing Exercise That Lifted Mood

The first Wednesday in November is Stress Awareness Day in the UK, and a lot of the advice handed out on the day comes down to “take a deep breath.” A small trial at Stanford University took that advice literally. It assigned 108 adults to one of four five-minute practices, done daily for a month, and asked them how they felt before and after each session.

The practice that stood out was cyclic sighing: two inhales through the nose, the second one topping up the lungs, then a long, slow exhale through the mouth, repeated for five minutes. In the trial it lifted positive mood more than the same five minutes of mindfulness meditation did. The gains were modest and the study was small, but the exercise costs nothing to try.

A Breath Your Body Already Takes

You sigh far more often than you notice. Spontaneous sighs, deeper breaths that arrive every few minutes, help reinflate the alveoli, the tiny air sacs in the lungs, and they become more frequent under stress. In 2016, researchers at Stanford and UCLA traced the reflex in mice to a cluster of about 200 neurons in the part of the brainstem that sets the breathing rhythm. When those cells were destroyed, the mice stopped sighing but, at first, kept breathing normally. It’s animal work, but it suggests a sigh has a dedicated circuit of its own.

Li, P. et al. (2016). “The peptidergic control circuit for sighing.” Nature, 530(7590), 293-297.

Cyclic sighing borrows that breath on purpose. One round is often called a physiological sigh, and repeating it for minutes on end is what makes it cyclic.

What the Stanford Trial Found

The trial ran entirely online between June and September 2020. Most participants were Stanford undergraduates, and people with conditions that breathing exercises might aggravate, such as heart disease, glaucoma, seizures, pregnancy or serious psychiatric illness, were excluded. Each person was randomly assigned to one practice for 28 days: cyclic sighing, box breathing, cyclic hyperventilation (rounds of 30 deep breaths followed by 15 seconds with empty lungs) or mindfulness meditation, which meant paying attention to the breath without controlling it. They rated their mood and anxiety before and after every session and wore a fitness band that tracked heart rate, breathing and sleep.

Every group felt better after its sessions, with less anxiety and fewer negative feelings, and on those measures meditation did as well as breathwork. The difference showed up in positive mood. On a scale that runs from 10 to 50, a session of cyclic sighing raised it by about 1.9 points on average, against about 1.2 after meditation. Box breathing and cyclic hyperventilation averaged similar gains, about 1.8 and 2.0. In the authors’ statistical model, which allowed for how many days each person had practiced, cyclic sighing was the only technique whose lead over meditation was statistically significant, and that lead grew the longer people kept at it.

Over the month, the daily breathing rate recorded by the band also fell more in the cyclic sighing group than in the meditation group. There were no significant changes in heart rate variability, resting heart rate or sleep.

Balban, M.Y. et al. (2023). “Brief structured respiration practices enhance mood and reduce physiological arousal.” Cell Reports Medicine, 4(1), 100895.

What One Small Trial Can’t Tell You

These are modest numbers, and the authors are open about the study’s limits. They describe it as exploratory, and it was registered only after it had run. Practice was self-reported, and on average people did their exercise on about 18 to 20 of the 28 days. Each group had between 21 and 33 people, too few to compare the breathing techniques with one another, so the trial doesn’t show that cyclic sighing beats box breathing. There was no follow-up after the month, and a group of mostly undergraduates may not respond the way older adults would.

Beyond this trial, a 2023 meta-analysis pooled 12 randomized trials with 785 adults and found that breathwork was linked to lower self-reported stress than control conditions, an effect the authors called small to medium. Results for anxiety and depressive symptoms were similar in size. Most of the trials were judged at moderate risk of bias, 10 of the 12 tested slow-paced breathing, and the search ended in February 2022, before the Stanford results came out. The authors cautioned against letting the hype outrun the evidence.

Fincham, G.W. et al. (2023). “Effect of breathwork on stress and mental health: A meta-analysis of randomised-controlled trials.” Scientific Reports, 13(1), 432.

Cyclic Sighing vs Box Breathing

Box breathing splits each breath into four equal parts: in for a count of four, hold for four, out for four, hold for four. It’s also called tactical breathing, because soldiers and police officers are taught it for high-pressure moments. In the Stanford trial, a short breathing test set each person’s count, from three to ten seconds. Cyclic sighing has no holds and puts the weight on the exhale. Each in-breath speeds the heart slightly and each out-breath slows it, and the authors predicted that exhale-focused breathing would help most.

Exhale-heavy breathing isn’t automatically the better choice, though. In a German laboratory study, 30 healthy people did a color-word test under time pressure and rising noise, using tactical breathing and prolonged exhalation in turn. How they felt didn’t differ between the two. Their physical arousal was lower with tactical breathing, while their test performance was better with the long exhales. The authors suggested box breathing may suit situations you have to sit through, and longer exhales situations where you have to act.

Röttger, S. et al. (2021). “The Effectiveness of Combat Tactical Breathing as Compared with Prolonged Exhalation.” Applied Psychophysiology and Biofeedback, 46(1), 19-28.

How to Do Cyclic Sighing for Five Minutes

These steps follow the trial’s instructions. Sit in a chair or lie down, and set a timer for five minutes.

1. Breathe in slowly through your nose until your lungs feel comfortably full.
2. Without breathing out, take a second, shorter inhale through your nose to fill them completely. It’s normal for it to be briefer than the first.
3. Breathe out slowly through your mouth until your lungs feel empty. This should be the longest part of the breath.
4. Repeat at an unhurried pace until the timer goes off, then breathe normally again.

If breathing out through your mouth feels odd, do it all through your nose, which the trial also allowed. Don’t force the second inhale. Light-headedness or tingling in your fingers usually means you’re overdoing it: stop and breathe normally. If you have a heart or lung condition, are pregnant or get panic attacks, check with your doctor before making this a daily habit, since the trial excluded several of those groups. Cyclic hyperventilation, the third technique, is more intense: skip it if you’re unsure, and never practice breath holds in water or while driving.

Lamplit’s free meditation tracker doesn’t have a cyclic sighing pattern, so you’d breathe it yourself. Pick the Mindfulness technique and a five-minute duration, and do your sighs while the timer runs. Try that for a week, then spend a week on the built-in Box Breathing, which paces a 4-4-4-4 rhythm for you. After each session, answer the journal’s free mood check-in (“How do you feel?”), and after two weeks compare both halves of the Mood Trend chart in the journal’s analytics. It won’t prove anything, but you’ll see how each week felt and learn which practice you actually keep doing.

Start a five-minute session in Lamplit’s meditation tracker and breathe in the cyclic sighing pattern. It’s free.