Stanford Study: Best Breathing Technique to Calm Down
- Jesse Coomer
- Mar 23
- 6 min read
Updated: Mar 25
I love simple tools that actually hold up when you test them.
Because when stress hits, you do not need a complicated ritual. You need something you can do in a chair, in your car, or before you walk into a tense conversation. You need something that works even when your brain is spinning.
That is why this Stanford study got my attention. Not because it “proved breathwork is amazing.” I already know breath changes state. It got my attention because they compared several popular practices head-to-head, and one stood out.
Not the one most people expect.
What Stanford actually tested (and what they found)
Here is the clean version of what happened.
Stanford researchers ran a remote randomized controlled trial where healthy volunteers practiced one assigned method for five minutes per day for about a month. The groups did one of three breathwork protocols (cyclic sighing, box breathing, or cyclic hyperventilation with breath retention) or a mindfulness meditation control.
They measured changes in:
State anxiety (before and after each daily session)
Mood (positive and negative affect)
Physiology using a wearable (including respiratory rate, resting heart rate, and heart rate variability)
Result: All groups improved anxiety and mood after sessions, including mindfulness meditation. But breathwork produced greater improvements in mood overall, and cyclic sighing showed the strongest signal for increasing positive affect and reducing respiratory rate over time.
One detail I appreciate: the researchers also noted the benefits of cyclic sighing tended to build with repeated days of practice. It was not just a one-off trick.
The method that stood out: cyclic sighing
Cyclic sighing is basically the physiological sigh breathing pattern: a double inhale followed by a long, slow exhale.
You might have heard it called:
cyclic sighing technique
double inhale breathing technique
Inhale twice, exhale once
2 breaths in 1 breath out
(Often mentioned as an Andrew Huberman breathing technique, since Huberman is a coauthor on the study and has talked about it publicly.)
Stanford’s instructions were straightforward:
Inhale slowly
When your lungs are expanded, inhale again to fill them more
Then exhale slowly and fully
Repeat for five minutes
They recommended both inhaling through the nose and exhaling through the mouth, but they also said you can do it all through the nose if you prefer.
How I teach it (simple, no drama)
Try this exactly as written the first time:
Inhale through your nose (steady, not forced)
Top off inhale (a second smaller inhale to fully expand)
Long exhale (slow, relaxed, empty the lungs)
Repeat, unbroken, for five minutes
If you are using this as a breathing technique to calm down in the moment, you can also do a short version:
One-minute “reset” version
Do three to five rounds of cyclic sighing
Then return to normal breathing and notice your shoulders, jaw, and belly
Most people feel a shift quickly, but the study’s daily practice was five minutes.
Why cyclic sighing may feel so calming
Two things stand out in the Stanford paper when they discuss why cyclic sighing might outperform other methods.
The extended exhale.
Longer exhalations tend to move the body toward a more parasympathetic, downshifted state. In the Stanford write-up, Spiegel explains it in plain terms: exhalation supports calming physiology.
The double inhale.
The paper highlights that cyclic sighing is different from the other techniques because it pairs extended exhalation with a double inhale that increases the depth of inhalation.
And here is the practical outcome that matters: over the month, cyclic sighing was linked with a stronger reduction in respiratory rate compared with mindfulness meditation. Lower resting breathing rate is often a good sign of “less revved up.”
A quick note on the “Stanford mouth breathing study” keyword
People often search for “Stanford mouth breathing study” around this topic. In the Stanford paper’s background section, they point to previous research suggesting nasal breathing can synchronize certain brain activity differently than mouth breathing.
I do not use that as a reason to panic about mouth breathing. I use it as a gentle nudge: when you can breathe through your nose comfortably, it is usually a good default.
How does this compare to other popular breathing methods
The Stanford study did not say “only do cyclic sighing.” It showed differences.
Box breathing
Box breathing is the classic “equal inhale, hold, exhale, hold” pattern. In the study, they actually customized timing using a simple CO2 discard duration test and then had participants match inhale, hold, exhale, and hold durations for five minutes.
When I like box breathing:
When someone wants steadiness and structure, especially before a performance moment.
Cyclic hyperventilation with retention
In the study, this looked like 30 deep breaths, then an exhale and a 15-second breath hold with lungs empty, repeated for three rounds within the session.
When I am careful with it:
This can be intense. If you are trying to calm down, this is not always the first tool I reach for.
Bottom line: cyclic sighing is the most “calm forward” of the three, because it emphasizes a long exhale and does not ramp you up.
A realistic way to practice (so it actually helps)
If you want the benefits that showed up in the data, do what they did:
The five-minute daily protocol
Pick one anchor time:
before work
after lunch
end of the workday
before bed (if it feels settling for you)
Then:
Set a timer for five minutes
Do cyclic sighing the whole time
Keep it gentle enough that you could keep going longer if you had to
If you miss a day, do not “make it up” with an aggressive session. Just return the next day. Consistency beats intensity.
Common mistakes I see (and what to do instead)
Forcing the inhale.
Fix: Keep the first inhale smooth. The second inhale is smaller by nature. Stanford even notes that it's normal.
Blasting the exhale.
Fix: Let the exhale be long and quiet. Think “release,” not “push.”
Doing it only when you are already panicking.
Fix: Practice daily when you are mostly fine. Then your body recognizes it faster when stress hits.
Safety notes (please read)
The Stanford trial involved healthy volunteers and excluded people with certain medical or psychiatric conditions (examples included heart disease, glaucoma, seizure history, pregnancy, psychosis, suicidality, bipolar disorder, and substance use disorders).
So:
If breath practices make you dizzy, numb, panicky, or unwell, stop and return to normal breathing.
If you have a medical condition or you are under mental health care, talk with your clinician before doing intense breathing practices.
Cyclic sighing is generally gentle, but your body gets the final vote.
FAQ
What is the cyclic sighing breathing technique?
Cyclic sighing is a controlled pattern where you inhale, take a second smaller inhale to fully expand the lungs, then exhale slowly and completely. You repeat this continuously for about five minutes in the Stanford protocol.
Is cyclic sighing the same as physiological sigh breathing?
Yes. Many people use “physiological sigh breathing” to describe the same pattern: a double inhale followed by a longer exhale. Stanford’s study used that structure and called it cyclic sighing.
How fast does this breathing technique work to calm down?
Some people feel calmer after one or two rounds, but the study tested five minutes daily over about a month and saw benefits build across days. For in the moment stress, do three to five rounds, then reassess.
What did Stanford compare cyclic sighing against?
They compared cyclic sighing against box breathing, cyclic hyperventilation with breath retention, and a mindfulness meditation control. All helped, but cyclic sighing showed the greatest improvements in positive affect and reductions in
respiratory rate over time.
Does this replace therapy or medication for anxiety?
No. Breathwork is a tool for state regulation and stress management, not a replacement for mental health care. The Stanford study also excluded people with moderate to severe psychiatric conditions, so it does not answer every clinical question.
Wrap up and next step
If you want one practice you can do anywhere, cyclic sighing is hard to beat. It is simple, it is repeatable, and it has real data behind it.
If you want to go deeper and learn how I program breathwork in a grounded way (without turning your life into a breathing project), check out my certification.
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