Cyclic Sighing: two inhales, one long exhale, on repeat

Cyclic sighing is the physiological sigh done on repeat: two inhales through the nose, one long exhale through the mouth, for about five minutes. One sigh takes the edge off in the moment. Five minutes of them, every day, was the breathing practice that did the most for mood in the Stanford trial.

What cyclic sighing is

The unit is one breath: a full inhale through the nose, a second short inhale on top of it without exhaling in between, and one slow, complete exhale through the mouth that lasts longer than both inhales together. The second inhale is what makes it different from a deep breath. Your body does this breath on its own every few minutes, usually without you noticing. Physiologists have described the sigh reflex since the 1930s, and in 2016 a team at Stanford and UCLA found the small cluster of brainstem neurons that fires it. Doing the breath on purpose, once or twice, is what Andrew Huberman named the physiological sigh in 2021. Doing it for five minutes is cyclic sighing, the practice David Spiegel's team at Stanford put through a trial in 2023. Same breath, two doses.

How to do cyclic sighing

1. Sit or lie down comfortably.
2. Inhale slowly through your nose until your lungs feel full.
3. Without exhaling, take a second, shorter sip of air on top, still through the nose.
4. Exhale slowly and completely through your mouth, longer than both inhales together, until you are empty.
5. That is one cycle. Keep going for five minutes, at your own pace, with no need to count.

In the moment, one to three cycles are enough to take the edge off. As a practice, five minutes once a day is the dose the trial used. In Breathtaking it is a guided video, so the pacing is done for you. If breathing practices are new to you, the beginner's guide covers what they all share.

What happens in your body

The second inhale reinflates the tiny air sacs in the lungs that collapse a little during ordinary breathing, which is what the reflex exists for in the first place. The long exhale slows the heart: breathing out engages the vagus nerve, the main brake of the nervous system, which is why a longer out-breath calms and a longer in-breath alerts. Over five minutes, the breathing rate itself drops, and it stays lower for a while after you stop. What you may feel is a drop in the chest, sometimes a yawn, and a loosening you did not ask for.

What it's used for

A wave of anxious energy. The minute before a hard conversation. A low, flat mood that a walk did not shift. The end of the day, when the day is still in your body. In the app's words: stress, emotional balance and, over weeks, mood.

What the research says about cyclic sighing

The main study is Balban et al., 2023, in Cell Reports Medicine, from Stanford. 108 people finished it. For 28 days they did five minutes a day of one of four things: cyclic sighing, box breathing, cyclic hyperventilation, or mindfulness meditation. Cyclic sighing improved daily mood the most and lowered resting breathing rate the most. Anxiety fell in all four groups by about the same amount. The more consecutive days people practiced, the bigger the effect. The limits are real: one trial, 30 people in the sighing group, done remotely with self-reported practice, and no change in heart rate or heart rate variability. The single sigh in the moment has never been tested on its own. The mechanism papers are older and steadier. Li et al., 2016, in Nature found the neurons that trigger a sigh, in mice. Vlemincx et al., 2016 showed that sighs reset breathing and that a deliberate deep breath raises the feeling of relief. Severs et al., 2022 reviewed what the sigh does for the lungs and the nervous system.

Where it comes from

Not a tradition, a reflex. Physiologists have studied sighing since the 1930s. The 2016 Nature paper found the roughly two hundred neurons that fire it. Huberman turned the single breath into a two-word instruction in 2021, and Spiegel's group tested the five-minute version in 2023. On the techniques page it sits with the modern methods.

When to use it

Once or twice, whenever the edge shows up: the sigh is the fastest tool in the library. Five minutes a day, at the same time each day, is where the trial's results came from, and the effect grew with each consecutive day. It does not build the steadier baseline that slower practices like 4-6 breathing build over months, which is why in a program it sits next to them rather than instead of them.

Cyclic sighing in Breathtaking

Breathwork. A guided video, in a five-minute version and a longer one. Calming; its job in the program is grounding. The program tends to pick it in weeks when your stress or emotional balance score is the one that needs moving and your profile responds to breath. In the app it is called Cyclic Sighing.

Frequently asked questions

Does cyclic sighing actually work?

In the Stanford trial, five minutes a day for a month improved daily mood more than mindfulness meditation and more than the other breathing practices tested, and lowered resting breathing rate. It is one trial with 30 people in the sighing group, so the honest word is promising, not proven.

How many times a day should you do cyclic sighing?

Once a day for five minutes is the practice. In the moment, one to three sighs are enough.

Is cyclic sighing the same as the physiological sigh?

Yes, at two doses. The physiological sigh is the single breath, done once or twice when you need it. Cyclic sighing is that breath repeated for five minutes as a daily practice.