Intensive Breathwork: Hyperventilation-Based Practices, Breath-Holding, Holotropic Breathwork and Cold-Plus-Breathwork Claims
A critical overview of intensive breathwork: what hyperventilation-based practices, breath-holding, Wim Hof-style and holotropic breathing are, what studies found, and the documented risks.
Content last updated . This page has not been medically reviewed.
What "intensive" practices have in common
Hyperventilation lowers carbon dioxide in the blood. MedlinePlus lists lightheadedness, dizziness, weakness, numbness and tingling in the arms or around the mouth, muscle spasms in the hands and feet, and a pounding heartbeat as effects. [1] Doing it deliberately produces the same effects, which some programs describe as a "release" or an altered state. That is an interpretation, not a medical finding.A 2023 review of "high ventilation breathwork" said reports of benefit for trauma-related, mood and bodily conditions invite further research and rigorous clinical testing. [2] That is insufficient evidence of benefit. It is not evidence of safety either.
The practices, one at a time
| Practice | What it is | What we found | Label |
|---|---|---|---|
| Wim Hof Method | Breathing, cold exposure and a mindset program taught by a Dutch founder | Small trials; lab inflammation markers changed in one controlled experiment; mixed or null results on mental health [3][4]. See Wim Hof Method: origins, claims and studies | Promising but limited (lab markers); insufficient evidence (health outcomes) |
| Wim Hof-style breathing in water | Fast breathing and breath-holding near or in water | Drownings reported in news coverage, none confirmed in court as caused by the method; hypoxic blackout is a documented mechanism [5][6]. See Wim Hof-style breathing and water | Evidence of harm (in water) |
| Holotropic Breathwork | Group session of accelerated breathing with music, led by certified facilitators | Descriptive reports and small studies; no randomized trial found in our search. See Holotropic Breathwork: origins, claims and risks | Insufficient evidence |
| Buteyko method | Breathing retraining for asthma that includes breath pauses | Small trials show symptom and reliever-use changes but no lung-function change [7]. See Buteyko method | Promising but limited (symptoms), no lung-function benefit shown |
| Cold exposure plus breathwork | Cold water or showers combined with fast breathing | Cold adds its own risks; see cold exposure plus breathwork claims | Insufficient evidence |
Prolonged breath-holding
Voluntary breath-holding, especially after hyperventilating, is the dangerous combination. In a 2023 experiment with 18 volunteers, 15 seconds of hyperventilation lengthened maximal breath-holds (133 versus 111 seconds) but left oxygen lower afterwards, and oxygen fell further across repeated holds. The authors said this could heighten the risk of a blackout. [8]A review of breath-hold diving physiology notes that deaths concentrate among less well-trained recreational divers who suffer from low oxygen. [9] A UK drowning-research group explains that "hypoxic blackout" does not depend on water depth and can occur in any depth of water. [6] Never practice breathwork or breath-holding in a bath, pool, lake, sea or shower. For more, see breath-holding risks and shallow water blackout and freediving and breath-hold sports.
Holotropic and similar group sessions
Holotropic Breathwork uses accelerated breathing and music in long group sessions. A 2025 study that tracked holotropic and conscious-connected sessions found that lower end-tidal carbon dioxide, from deliberate hyperventilation, was linked with the onset of altered states, and that deeper states predicted self-reported improvement in well-being and depressive symptoms afterward. [10] That describes what happens during a session. It is not a controlled trial of treatment, and it cannot show the breathing itself caused the gains. We looked for randomized trials or systematic reviews of holotropic breathwork for treatment or safety and found none: proper evidence not found.Claim check
| Claim | What we found | Label |
|---|---|---|
| Breathing plus cold strengthens immunity or treats disease | Small trials; some lab markers changed, no proof of better health outcomes [12][3] | Insufficient evidence |
| Hyperventilation breathwork heals trauma | Reviews call for clinical testing [2] | Insufficient evidence |
| Breath-hold training with prior hyperventilation is safe if done carefully | Hyperventilation leaves oxygen lower at the end of a hold [8] | Evidence of harm (in water) |
Frequently asked questions
Is the Wim Hof Method safe?
Its own website says intensive rounds can in rare cases cause loss of consciousness and that this can be very dangerous in or near water or when driving. [13] The evidence for benefit comes from small trials, most at high risk of bias. [14]
Does hyperventilating before a breath-hold help you hold longer?
It can lengthen the hold, but it left oxygen levels lower afterwards in one experiment, which can lead to blackout. [8]
Is holotropic breathwork evidence-based?
Proper evidence not found for treatment effects. A 2025 study described altered states during sessions, not treatment outcomes. [10]
Can I do any of this in a pool or bath?
No. Hypoxic blackout can occur in any depth of water. [6]
What should I do instead if I want to try breathing for stress?
Start with slower, gentle practices in a safe setting and check with your clinician if you have a health condition. See the stress breathing overview. NCCIH says relaxation techniques are generally considered safe for healthy people, with rare exceptions. [11]
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
Safety first, and why this page has no instructions
Gentler practices are covered in gentle breathing and relaxation practices and in the breathwork safety guide.
Who should avoid these practices
References
- MedlinePlus Medical Encyclopedia, Hyperventilation. U.S. National Library of Medicine. Read 2026-10-22.
- High ventilation breathwork practices: an overview of their effects, mechanisms, and considerations for clinical applications. 2023. Read 2026-10-22.
- Does the Wim Hof Method have a beneficial impact on physiological and psychological outcomes? A systematic review. PLoS One 2024. Read 2026-10-22.
- Randomized controlled clinical trial of a Wim Hof Method intervention in women with high depressive symptoms. Compr Psychoneuroendocrinology 2024. Read 2026-10-22.
- Live Science, 'Gambling with your life': Experts weigh in on dangers of the Wim Hof method. Patrick Pester, 5 April 2024. Read 2026-10-22.
- Water Incident Research Hub (UK), Guidance: What is a hypoxic blackout? 7 December 2021. Read 2026-10-22.
- Effect of two breathing exercises (Buteyko and pranayama) in asthma: a randomised controlled trial. Thorax 2003. Read 2026-10-22.
- Effects of hyperventilation on oxygenation, apnea breaking points, diving response, and spleen contraction during serial static apneas. 2023. Read 2026-10-22.
- The physiology and pathophysiology of human breath-hold diving. J Appl Physiol 2009. Read 2026-10-22.
- Decreased CO2 saturation during circular breathwork supports emergence of altered states of consciousness. 2025. Read 2026-10-22.
- NCCIH, Relaxation Techniques: What You Need To Know. U.S. National Institutes of Health. Read 2026-10-22.
- Voluntary activation of the sympathetic nervous system and attenuation of the innate immune response in humans. PNAS 2014. Read 2026-10-22.
- Wim Hof Method, Breathing exercises page. Company website. Read 2026-10-22.
- University of Warwick press release, Does the Wim Hof method really work? (last revised 14 March 2024). Read 2026-10-22.