Short version: better evidenced than almost any breathing technique you have heard of, and still one trial. Here is what the Stanford study actually measured, what it found, and where a careful reader should hold back.
The answer. A randomized controlled trial at Stanford, published in Cell Reports Medicine in 2023, found that five minutes a day of cyclic sighing improved mood and lowered resting respiratory rate more than mindfulness meditation over a month. It is the best-evidenced breathing protocol in our library, and it is still a single trial.
A double inhale followed by a long exhale. Breathe in through the nose, then take a second short sip of air on top when you think you are full, then let it out slowly through the mouth until it runs down to nothing.
You have done it thousands of times without deciding to. It is the shape of the breath after crying, and the catch of air a sleeping child takes. The physiological sigh is the single breath. Cyclic sighing is doing it on purpose, repeatedly, for a few minutes.
Participants were randomized across four groups: cyclic sighing, box breathing, cyclic hyperventilation, and mindfulness meditation. Each did five minutes a day for a month. Researchers tracked mood, anxiety, and physiological measures including respiratory rate.
Cyclic sighing came out ahead on daily mood improvement, and produced the largest reduction in resting respiratory rate. Notably, all four groups improved. The finding is that this one improved more, not that the others did nothing.
The full paper is linked from our page on the technique and in the evidence audit, so you can read the methods rather than take our summary for it.
We grade this Strong, which for us means randomized evidence supports the specific effect claimed. That is a high bar for a breathing technique and a low bar for medicine.
None of that makes it weak. It makes it a good, early, well-run result, which is genuinely more than most of what gets called science-backed in this category.
Box breathing has Navy SEALs and a memorable name. 4-7-8 has a famous doctor and a viral shape. Cyclic sighing has a randomized trial and a name nobody can quite remember, so it loses every popularity contest it enters.
If you are picking one breathing technique on evidence rather than on how good it sounds, this is the one to pick. Compare it against the alternatives in our box breathing versus 4-7-8 guide.
No counting, no app strictly required. If you want it paced and sequenced with whatever else your day needs, that is what Shora does.
Yes, with the caveats any single trial deserves. A randomized controlled trial at Stanford, published in Cell Reports Medicine in 2023, found five minutes a day improved mood and lowered respiratory rate more than mindfulness meditation over a month. It is one trial, in mostly healthy adults, so treat it as strong for a breathing technique rather than settled science.
The single breath: a full inhale, a second short sip of air on top, then a long slow exhale. Your body already does it spontaneously when you are crying or falling asleep. Cyclic sighing is the practice of repeating it deliberately for a few minutes.
One or two sighs are usually noticeable. The trial measured its effects from five minutes a day over a month, so the immediate relief and the cumulative benefit are two different claims.
In that one trial, for mood and breathing rate, over 28 days, it beat mindfulness meditation. That is a narrow result and not a general ranking. It is fair to say it is faster to learn and takes less time per day.
Shora picks between these for you, based on a thirty-second check-in, and learns which one actually works for you. Free on iOS and Android, no account needed to start.
This is general information about wellness practices, not medical advice. If you are struggling, a licensed professional is the right call.
