Transcription
In 2023, a Stanford team led by David Spiegel and Andrew Huberman ran a head-to-head comparison of three breathing techniques against mindfulness meditation. The techniques were box breathing, the one the Navy SEALs use, cyclic hyperventilation with retention, very akin to the Wim Hof method breathing, and a third technique that sounds on paper like the weakest of the four, cyclic sigh.
More specifically, cyclic sigh. Two inhales stacked together followed by one long exhale. You will also hear it called the physiological sigh. The reason for the physiological label is that this exact breath pattern is something your body already produces on its own, automatically dozens of times a day. But when it's a day of doing it deliberately for a month, and the cyclic sigh group came out on top. Biggest jump in mood, biggest drop in breathing rate. And the longer people stayed with it, the more the effect compounded.
Today, I want to show you exactly how to do the cyclic sigh, and then take it two levels deeper than the study did, because once you understand what this breath actually is, you can build it into almost every other breathing practice you know. Most breathing techniques ask something from you, a timer, a quiet room, a metronome, or a guided video, or a complicated load of counting. And that's partially why almost nobody uses them in the moments they were designed for, in the moment before an important meeting, or in other words, always when your emotions are high, you're under pressure, or under stress.
The physiological sigh has none of that overhead. Two inhales and a long exhale. No counting, no specific app. You can do it folding laundry or while doing something else. What I've been finding in my own practice and what I'll show you in a minute is that the same simple structure also becomes a building block for almost everything else.
The cyclic sigh isn't a human invention. It's a reflex you share with every other mammal on this planet. In 2016, a team at Stanford and UCA traced the sigh reflex in mice down to a specific population of about 200 neurons in the brainstem. When they knocked those neurons out, the mice stopped sighing entirely, but every other kind of breathing kept going normally. So, there's a small dedicated circuit in the mammalian brain whose only job is to generate this exact breath pattern. A double inhale followed by a longer exhale.
In humans, that circuit fires roughly once every 5 minutes when you're awake. You sigh without thinking about it after sustained focus, before falling asleep, after a long cry. The reflex reinflates small sections of lung tissue that collapses during regular breathing. And it tends to mark transition between states, moving from one activity to another, for example, from arousal towards calm. Cyclic sigh the technique is just the deliberate, repeated version of this breathing reflex.
Now, let's go to the actual mechanics. When you exhale, your heart rate drops. That's the parasympathetic side of your nervous system doing its job. The calming side. When you inhale, your heart rate rises slightly. This is called respiratory sinus arrhythmia, and it's happening on every breath you take. That Stanford 2023 paper points to this as the reason a longer exhale is more calming than a longer inhale. You're giving the vagus nerve more time to do its work.
The cyclic sigh stacks the deck twice. The double inhale maximizes the depth of your breath in a way a single inhale can't quite reach. Then the long, slow exhale takes it down to the parasympathetic side of the curve.
Two things the Stanford team noticed that I think are worth knowing before you practice this technique. First, the benefit compounded over the month. The longer people stayed with the 5 minutes a day of practice, the bigger the mood lift became. Second, the change in breathing rate tracked along with the change in mood. People whose respiratory rates dropped the most had the biggest gains in positive effect in mood as well. So, slowing the breath isn't just an outcome. It seems to be part of the mechanism.
One honest note of caveat I want to make here. The same study found there was no significant change in heart rate variability or resting heart rate over the month. So, if you're tracking your HRV on a wearable, like the Whoop band for example, and don't see it move during those 4 weeks, that's consistent with the data of the study. The wins are mostly in the mood and in the respiratory rate.
So, before we start with the breathing itself, I want to say that posture matters more than people think. But not for the reasons most teachers give you. It's isn't about discipline or about looking looking good. It's about awareness. A tall spine or lying flat on your back gives the diaphragm room to descend without anything in its way. The descent of the diaphragm is a subtle movement, and the only way you feel the difference between a real diaphragmatic inhale and a throat-initiated sip is if your posture lets that subtle movement actually register. Slouch or having a too rigid posture disturbs the exact signal you're trying to learn.
So, sit tall but soft. Imagine a string at the crown of your head pulling you gently upwards. Let the image do the work, not your muscle. Or lie down on your back, as you prefer. That works as well. Then run your awareness down the body, jaw, neck, shoulder, chest, belly. Let everything around the spine surrender to gravity.
Now that you feel the breath, let's go to the movement of the breath. Step one, first the inhale. Inhale deeply into the belly through the nose. Aim below the navel area like you're inflating the bottom of the balloon. Your throat stays soft. Put a finger on your throat if you need the feedback. There shouldn't be any tension there when you inhale.
Step two, continue the inhale to the rib cage. Smooth and no pause. Expand the ribs in all direction, front, the sides, and also the back. This is the part most people skip, but actually trains a deeper breathing.
Step three is the second sip. When you feel fully inhaled, take one more short sniff. Just a little sip of air at the top. You will feel a small pressure build under the collarbone. That's the defining feature of the physiological sigh or the double inhale.
Step four, long and slow exhale. No force, just release. Make it longer than the inhale was. The standard protocol used the mouth for the exhale with the option to keep it through the nose if it feels better this way. Either works. Use the exhale as a cue. Each second going out, let let something go and create space in your mind and in your body.
I find 5 minutes is very manageable for almost all circumstances. But honestly, I have found that even a few breaths can already help calm me a little in a moment of high stress or emotions. So that I don't react less impulsively and regain a sense of control in that stressful moment.
One thing you want to be aware of or use as a checkpoint during the first inhale, the throat should be passive. If you feel contraction there, you're initiating from the wrong place. Back off and let the diaphragm lead. The distinction between diaphragm led versus throat led breathing is one of the most useful things this technique teaches you that you can implement into other techniques.
Quick note before we move on. What you just learned is just one small part of deliberate breathing or mindfulness can do for you. There are so many more techniques that work in different ways. Some for energy, some for focus, some for sleep, and some for shifting your state on demand. And because so many people ask me what breathing techniques they should use for this or that situation, I've put them together into a free 15-day email and video course. One technique a day with a guided video for each. The link is in the description if you want to dive deeper after watching this video.
So once this high feels natural on its own, you can use it as a baseline inside other techniques. Coherence breathing is one of the simplest patterns in the research literature of breathing. 6 seconds in, 6 seconds out. 5 breaths a minute. It's the rate where heart rate variability is the highest and the parasympathetic system is the most engaged. And here's how to layer the sigh in the coherent breathing technique. For the 6 second inhale, you do the full diaphragm then rib cage pattern and you fit in the second sip right at the end of the 6 seconds.
So, the entire inhale becomes a long, smooth, two-part rise as you fill up your lungs much more fully. The exhale stays as it was, 6 slow seconds out through the nose. So, this is what this does. It forces you to feel the difference between diaphragm led and throat led breathing in a sustained way. Because the inhale is now 6 second long, you have time to notice if you're pulling from the throat or from the diaphragm. Because if you're pulling from the throat, the second sip doesn't really work. You're limiting the diaphragm's ability to descend fully and with that, take a full inhale.
A few minutes of coherent breathing with the sigh added into it will drop you into a different gear than other techniques on its own. This double inhale after cyclic sigh maximizes lung volume. The long exhaling at 6 seconds maximizes the parasympathetic pull. So, both are stacked together. They reinforce each other and make the technique more effective.