What breathwork is, and what it actually does

Breathing is the automatic bodily function you can most easily take over. You cannot slow your heart by command. You cannot speed up digestion on request. But you can change your breath right now, mid-sentence, while reading this. Breathwork begins at that single opening.

The term is used loosely. Practices that are almost physiologically opposite sit under the same heading. This piece separates them, and says plainly how much evidence stands behind each.

A definition

Breathwork is a structured practice of deliberately altering the rhythm, depth and retention of the breath in order to influence physiological and emotional state. It is not simply taking a deep breath. A specific pattern is repeated for a specific duration with a specific intention.

The rhythm generator for breathing sits in the brainstem, in a small cluster of neurons called the preBötzinger complex. The 2018 review by Del Negro, Funk and Feldman describes it as far more than a metronome. It coordinates breathing with speech, swallowing and chewing, and it both influences and is influenced by emotion and cognition.

The conclusion is simple and important. Breath is not merely a downstream output of mood. The circuit can be entered from either end.

Four main methods

Diaphragmatic breathing. The foundation. Letting the belly expand while the chest stays relatively quiet. Most people breathe shallowly through the upper chest all day. Bringing the diaphragm back online is the ground everything else is built on.

Slow and coherent breathing. Any practice that drops below ten breaths per minute. The usual target is five to six. That range is not arbitrary: it matches the natural oscillation of the feedback loop between heart rate, blood pressure and the baroreflex. This is where the evidence is firmest.

Conscious connected breathing. Continuous, circular breathing with no pause between inhale and exhale. Sessions run from twenty minutes to an hour and are usually facilitated. Strong emotional release, tingling and cramping in the hands and face (tetany) are common. These are not mystical events. They are the known consequences of carbon dioxide dropping quickly in the blood.

Wim Hof and high-ventilation methods. Around thirty fast, deep breaths followed by a long retention on empty lungs, repeated over several rounds. This produces temporary respiratory alkalosis followed by falling oxygen saturation. The effect is sharp. So is the risk.

What the evidence says

Advocates and critics often make the same mistake: they put every method in one bag and judge the bag. The evidence differs markedly from method to method.

For slow breathing, the evidence is reasonable. Zaccaro and colleagues' 2018 systematic review screened 2,461 abstracts and found 15 studies that met criteria. Slow breathing consistently increased heart rate variability and respiratory sinus arrhythmia, increased alpha and decreased theta power on EEG, and participants reported relaxation and comfort. The authors' own caveat matters just as much: the literature lacks a standardised methodology, samples are small, and heterogeneity made meta-analysis impossible.

For short daily practices, there is one interesting finding. Balban and colleagues, publishing in Cell Reports Medicine in 2023, randomised 108 participants to one of three five-minute daily breathing practices or to mindfulness meditation for a month. The exhale-emphasised "cyclic sighing" group showed the largest increase in positive affect, significantly greater than the meditation group, alongside a greater reduction in respiratory rate. The same study found no significant change in heart rate variability, resting heart rate or sleep measures. That detail is usually omitted. It should not be.

Across the field, effect sizes are small to moderate. Fincham and colleagues' 2023 meta-analysis pooled 12 randomised controlled trials and 785 participants for stress. The result was statistically significant but modest (g = −0.35). Anxiety and depressive symptoms showed similar magnitudes. The authors noted that most included studies carried a moderate risk of bias.

For high-ventilation methods, the picture is murkier. The same research group published a placebo-controlled trial in 2024 with 200 participants. Three weeks of twenty minutes a day of high-ventilation breathwork with retention did not significantly outperform a comparison practice at 15 breaths per minute. Both groups improved; the difference between them was not significant. This does not mean the method does nothing. It means the claim that it does something special has not yet survived a well-designed comparator.

Kox and colleagues' 2014 study is widely cited. Twelve people trained for ten days in high-ventilation breathing and cold exposure showed higher adrenaline and lower inflammatory markers than controls when given an endotoxin. The finding is real and significant. But it is an acute laboratory response, measured in a total sample of 24 young, healthy volunteers. It does not mean the practice protects against illness in daily life.

What breathwork is not

It is not medical treatment. No breathing practice cures a condition, replaces medication, or substitutes for psychotherapy. Do not trust any source that fails to say this clearly.

It is not a trauma processing method, at least not on its own. Intense sessions can surface powerful emotional material. What to do with that material is a separate professional competence, and a breathwork certificate does not confer it.

It is also not an intervention that shifts everything measurable. The evidence is stronger for subjective wellbeing and perceived stress than for hard physiological markers.

The right frame is this: breathing is a self-regulation skill. It is learned, refined, and becomes reliable over time. What we do at Nefesora is teach that skill. Nothing more is promised.

A note on safety

If you are pregnant, or live with uncontrolled hypertension, arrhythmia or other cardiovascular conditions, epilepsy, glaucoma, panic disorder or a significant psychiatric history, consult your physician before beginning intensive breathing practices.

Never practise breath retention in or near water, in a bath, or while driving. Hyperventilation followed by retention delays the body's urge to breathe while oxygen continues to fall. That combination has been fatal in water. Always practise seated or lying down.

Tingling, dizziness and cramping in the hands are expected and temporary in high-ventilation practices, and resolve on return to normal breathing. Chest pain, fainting or a symptom that does not pass is a different matter. Stop, and see a doctor.

Sources

• Del Negro CA, Funk GD, Feldman JL. Breathing matters. Nature Reviews Neuroscience, 2018. nature.com/articles/s41583-018-0003-6
• Zaccaro A et al. How Breath-Control Can Change Your Life: A Systematic Review on Psycho-Physiological Correlates of Slow Breathing. Frontiers in Human Neuroscience, 2018. frontiersin.org
• Balban MY et al. Brief structured respiration practices enhance mood and reduce physiological arousal. Cell Reports Medicine, 2023. pmc.ncbi.nlm.nih.gov/articles/PMC9873947
• Fincham GW et al. Effect of breathwork on stress and mental health: a meta-analysis of randomised-controlled trials. Scientific Reports, 2023. pubmed.ncbi.nlm.nih.gov/36624160
• Fincham GW et al. Effects of brief remote high ventilation breathwork with retention on mental health and wellbeing. Scientific Reports, 2024. pmc.ncbi.nlm.nih.gov/articles/PMC11266346
• Kox M et al. Voluntary activation of the sympathetic nervous system and attenuation of the innate immune response in humans. PNAS, 2014. pnas.org/doi/10.1073/pnas.1322174111