Does breathwork work, and what about the Wim Hof method?

Does five minutes of breathwork actually do anything?

Yes. A 2023 Stanford randomised trial ran 100 people through 28 days of five-minute daily practice across four arms. All breathing techniques improved mood more than mindfulness meditation, and cyclic sighing, which emphasises a long exhale, produced the largest improvement and the biggest drop in breathing rate.

The study was published in Cell Reports Medicine by Balban and colleagues, including David Spiegel and Andrew Huberman. Four arms: mindfulness meditation as the comparison, cyclic sighing, box breathing, and cyclic hyperventilation with retention.

The result worth carrying is that the exhale mattered. Cyclic sighing means two inhales through the nose then a long slow exhale through the mouth, and it beat the other patterns on positive mood. Drop in breathing rate tracked with improvement in mood across participants, which gives a plausible physiological account.

What the trial found on other measures deserves equal billing. State anxiety and negative mood fell in every arm including meditation, with no difference between them, and sleep did not change at all in any group.

Limitations are stated by the authors: remote delivery with self-reported adherence, four weeks with no follow-up, and small numbers in each individual breathing arm. One author became an advisor to WHOOP, the wearable used in the study, in 2022; the company had no role in the design or analysis.

Does the Wim Hof method have real evidence?

It has one striking finding. In a 2014 PNAS study, 24 healthy men were injected with bacterial toxin after some had trained in the method. The trained group produced far more adrenaline, released more anti-inflammatory signalling, showed inflammatory markers reduced by roughly half, and had milder symptoms and fever.

Kox and colleagues ran this at Radboud University. Twelve trained participants against twelve controls, with a ten-day programme of breathing, meditation and cold exposure. The demonstration that a voluntary practice can measurably blunt an induced immune response was genuinely new.

The limits are as important as the finding. Twenty-four healthy young men. The authors state they cannot tell which component, the breathing, the cold, or the meditation, produced the adrenaline surge, and that the result may not extend to people with chronic inflammatory disease.

A single dramatic finding in two dozen people is a starting point. The claims made in its name have travelled a great deal further than the evidence has.

Does believing it works make it work?

Partly, on this evidence. A follow-up study of the same training found that general optimism correlated strongly with the adrenaline response and with the anti-inflammatory response, and that people who expected the training to help reported fewer flu-like symptoms.

Van Middendorp and colleagues reported these correlations in Clinical Rheumatology in 2015. Optimism against adrenaline came out at rho 0.76, and against the anti-inflammatory marker IL-10 at rho 0.60. Expectation of benefit tracked with reduced symptoms at rho -0.71.

This is a small sample and the authors call for replication before anyone leans on it. It is worth including because it is the kind of finding usually left out. Expectancy shaping a physiological outcome is real, well documented across medicine, and it complicates any simple claim that the technique alone did the work.

For you as a practitioner this changes little. A practice that works partly through expectation still works. It matters when someone tells you the mechanism is settled.

What is safe to try?

Cyclic sighing carries essentially no risk and has the best evidence for daily use. Techniques involving hyperventilation or breath holding are a different matter, and the well-documented danger is losing consciousness.

Never practise breath holding or hyperventilation in or near water, in a bath, or while driving. Shallow water blackout has killed experienced swimmers. Practise lying down or seated, on land, with nothing to fall against.

If you are pregnant, live with epilepsy, cardiovascular disease, or a history of panic, speak to a clinician before starting intense breathwork. Cold exposure carries its own cardiac considerations.

The practical summary from the Stanford trial: five minutes, daily, exhale longer than you inhale. That is the part with controlled evidence behind it, and it is also the safest part.