Breath retention (kumbhaka, Wim Hof)

Breath retention (kumbhaka) is a core element of hatha yoga pranayama, which the tradition holds calms the mind and prepares it for meditation. The Wim Hof method pairs rounds of deep, fast breathing with long breath-holds, cold exposure and meditation; a small 2014 trial found a dampened inflammatory response to experimental endotoxin in trained healthy volunteers, but later trials on stress, mood and cardiovascular measures were mixed or null. The best-established finding is a harm: hyperventilating and then holding the breath in or under water can cause sudden loss of consciousness and drowning, and the Wim Hof organisation's own materials warn against practising near water.

Mind
Recovery

Evidence retrieved up to 16 October 2026

What the research shows

In a small randomised trial, healthy volunteers trained for ten days in the Wim Hof method (cyclic hyperventilation followed by breath retention, cold exposure and meditation) showed lower pro-inflammatory cytokines and fewer flu-like symptoms after an experimental endotoxin challenge than untrained controls.

Low certainty

Further research is likely to change this.

Take care: see the safety noteBenefit

Who this is about

healthy adult volunteers

Practical note

Graded low: one randomised trial of 24 healthy volunteers, unblinded, measuring a laboratory response to injected endotoxin; the training combined breathing, cold immersion and meditation, so the share due to breath retention is unknown. A 2024 systematic review of eight trials was positive about inflammation but did not pool results.

Vegan note

Not diet-related; applies equally to people following a vegan diet.

Safety note

The breathing produced intermittent low blood oxygen. It should never be practised in or near water, including ice baths, because of the risk of blackout and drowning. People who are pregnant or living with heart, lung or mental-health conditions are generally advised to check with a health professional first.

Sources

Supports “Levels of proinflammatory mediators TNF-α, IL-6, and IL-8 were lower in the intervention group and correlated negatively with IL-10 levels. Finally, flu-like symptoms were lower in the intervention group.” (Abstract) Kox M, van Eijk LT, Zwaag J, van den Wildenberg J, Sweep FC, van der Hoeven JG, Pickkers P. 2014. Proceedings of the National Academy of Sciences of the United States of America. Voluntary activation of the sympathetic nervous system and attenuation of the innate immune response in humans. publisher copyright; metadata and short quotes only; Courtesy of the U.S. National Library of Medicine
Supports “The findings suggest that the WHM may reduce inflammation in healthy and non-healthy participants as it increases epinephrine levels, causing an increase in interleukin-10 and a decrease in pro-inflammatory cytokines.” (Abstract, Results) Almahayni O, Hammond L. 2024. PLoS One. Does the Wim Hof Method have a beneficial impact on physiological and psychological outcomes in healthy and non-healthy participants? A systematic review. CC BY 4.0; credit Almahayni and Hammond, PLoS One 2024; Courtesy of the U.S. National Library of Medicine
Context “Subjects in the intervention group were trained for 10 d in meditation (third eye meditation), breathing techniques (i.a., cyclic hyperventilation followed by breath retention), and exposure to cold (i.a., immersions in ice cold water).” (Abstract) Kox M, van Eijk LT, Zwaag J, van den Wildenberg J, Sweep FC, van der Hoeven JG, Pickkers P. 2014. Proceedings of the National Academy of Sciences of the United States of America. Voluntary activation of the sympathetic nervous system and attenuation of the innate immune response in humans. publisher copyright; metadata and short quotes only; Courtesy of the U.S. National Library of Medicine

Randomised trials of the Wim Hof method on stress, mood and cardiovascular measures show mixed results: in one trial daily practice for 15 days had no effect on blood pressure, heart rate variability or psychological measures versus control, and in another it produced the same improvements in stress, anxiety and low mood as slow-paced breathing.

Low certainty

Further research is likely to change this.

Take care: see the safety noteUnclear

Who this is about

adults, including midlife women with high stress

Practical note

Graded low: two small randomised trials (42 and 84 participants) with short interventions and self-reported psychological outcomes, and results that do not show an advantage over control or slow breathing. Interventions ran for two to three weeks, with daily sessions of about 15 minutes in one trial.

Vegan note

Not diet-related; applies equally to people following a vegan diet.

Safety note

All participant dropouts in one trial came from the Wim Hof arm. The breathing should never be practised in or near water because of the risk of blackout and drowning.

Sources

Supports “Counter to the preregistered predictions, and despite participants' differing expectations, the interventions led to equivalent reductions in depressive symptoms, anxiety symptoms, and perceived stress, which were sustained at three months.” (Abstract, Conclusions) Blades R, Mendes WB, Don BP, Mayer SE, Dileo R, O'Bryan J, Fromer E, Guan JY, Cheng SS, Mason AE, Prather AA, Epel ES. 2024. Comprehensive Psychoneuroendocrinology. A randomized controlled clinical trial of a Wim Hof Method intervention in women with high depressive symptoms. publisher copyright; metadata and short quotes only; Courtesy of the U.S. National Library of Medicine
Supports “Performing the WHM daily did not exert positive effects on cardiovascular and psychological parameters.” (Abstract) Ketelhut S, Querciagrossa D, Bisang X, Metry X, Borter E, Nigg CR. 2023. Scientific Reports. The effectiveness of the Wim Hof method on cardiac autonomic function, blood pressure, arterial compliance, and different psychological parameters. publisher copyright; metadata and short quotes only; Courtesy of the U.S. National Library of Medicine
Context “Differential attrition was observed with six participants (7 %) dropping out -- all from WHM condition.” (Abstract, Results) Blades R, Mendes WB, Don BP, Mayer SE, Dileo R, O'Bryan J, Fromer E, Guan JY, Cheng SS, Mason AE, Prather AA, Epel ES. 2024. Comprehensive Psychoneuroendocrinology. A randomized controlled clinical trial of a Wim Hof Method intervention in women with high depressive symptoms. publisher copyright; metadata and short quotes only; Courtesy of the U.S. National Library of Medicine
Context “Additionally, effect of WHBM on exercise performance showed mixed findings.” (Abstract, Results) Almahayni O, Hammond L. 2024. PLoS One. Does the Wim Hof Method have a beneficial impact on physiological and psychological outcomes in healthy and non-healthy participants? A systematic review. CC BY 4.0; credit Almahayni and Hammond, PLoS One 2024; Courtesy of the U.S. National Library of Medicine

Hyperventilating and then holding the breath in or under water can cause sudden loss of consciousness (hypoxic or shallow-water blackout) and drowning, even in healthy swimmers and shallow water, and the Wim Hof organisation's own materials warn against practising near water because of this risk.

Moderate certainty

Further research may change the size of the effect.

Caution: see the safety noteRisk

Who this is about

people who practise hyperventilation followed by breath-holding in or near water

Practical note

Graded moderate: the evidence is case reviews and clinical reference material rather than trials, but the outcome is severe, the reports are consistent, the physiology is well understood, and combining several such behaviours raised the risk of death. The Wim Hof organisation's own materials warn against practising the breathing near water.

Vegan note

Not diet-related; applies equally to people following a vegan diet.

Safety note

Never practise hyperventilation or breath retention, including Wim Hof breathing, in or near water: pools, baths, ice baths, the sea or open water. Blackout can happen without warning at any depth.

Sources

Supports “In 2011, two healthy young men died in a drowning incident at a New York City (NYC)-regulated swimming facility. The men became unconscious underwater after performing intentional hyperventilation before submersion.” (Abstract) Boyd C, Levy A, McProud T, Huang L, Raneses E, Olson C. 2015. MMWR Morbidity and Mortality Weekly Report. Fatal and nonfatal drowning outcomes related to dangerous underwater breath-holding behaviors - New York State, 1988-2011. U.S. government (CDC) publication; metadata and short quotes only; Courtesy of the U.S. National Library of Medicine
Supports “the loss of consciousness in the underwater swimmer or diver, during an apnea submersion preceded by hyperventilation, where alternative causes of unconsciousness have been excluded." Shallow water blackout can occur in any body of water at any depth.” (Abstract) Bart RM, Murray BP, Lau H. 2026. StatPearls (StatPearls Publishing). Shallow Water Blackout. StatPearls Publishing copyright; metadata and short quotes only; Courtesy of the U.S. National Library of Medicine
Supports ““Engaging in these exercises near water increases the risk of shallow water blackout, which can lead to drowning and, tragically, death,” one disclaimer reads.” (Article body, quoting a Wim Hof app disclaimer) Dreier F. 2023. Outside. Iceman Wim Hof Is being Sued for the Death of a California Teenager. Outside Interactive, all rights reserved; short attributed quotes only; credit Outside
Context “For this small sample, the frequency of different DUBBs varied by age and swimming level, and practicing more than one DUBB increased the risk for fatality.” (Abstract) Boyd C, Levy A, McProud T, Huang L, Raneses E, Olson C. 2015. MMWR Morbidity and Mortality Weekly Report. Fatal and nonfatal drowning outcomes related to dangerous underwater breath-holding behaviors - New York State, 1988-2011. U.S. government (CDC) publication; metadata and short quotes only; Courtesy of the U.S. National Library of Medicine

In one randomised trial, young adult yoga practitioners who added 20 minutes of yoga breathing with intermittent breath holding to their usual yoga for eight weeks scored better on state mindfulness, mind-wandering and state anxiety than those practising yoga alone.

Low certainty

Further research is likely to change this.

Take care: see the safety noteBenefit

Who this is about

young adult yoga practitioners

Practical note

Graded low: a single randomised trial of 116 yoga practitioners with self-reported outcomes and no blinding; it has not been replicated. The added practice ran for 20 minutes over eight weeks.

Vegan note

Not diet-related; applies equally to people following a vegan diet.

Safety note

Breath holding should never be practised in or near water. People who are pregnant or living with heart, lung or mental-health conditions are generally advised to check with a health professional before taking up breath-holding practices.

Sources

Supports “At the end of 8 weeks, both groups demonstrated enhanced psychological functions, but the experimental group receiving additional yoga breathing performed better than the group practicing yoga alone.” (Abstract, Results) Saoji AA, Raghavendra BR, Madle K, Manjunath NK. 2018. Explore (NY). Additional Practice of Yoga Breathing With Intermittent Breath Holding Enhances Psychological Functions in Yoga Practitioners: A Randomized Controlled Trial. publisher copyright; metadata and short quotes only; Courtesy of the U.S. National Library of Medicine
Context “State mindfulness attention awareness scale (SMAAS), Mind-Wandering Questionnaire (MWQ) and State anxiety inventory were administered at baseline and at the end of 8 weeks.” (Abstract, Methods) Saoji AA, Raghavendra BR, Madle K, Manjunath NK. 2018. Explore (NY). Additional Practice of Yoga Breathing With Intermittent Breath Holding Enhances Psychological Functions in Yoga Practitioners: A Randomized Controlled Trial. publisher copyright; metadata and short quotes only; Courtesy of the U.S. National Library of Medicine

What the tradition holds

The hatha yoga tradition holds that breath retention (kumbhaka), practised within pranayama, calms the mind and, done correctly, purifies the energy channels.

Take care: see the safety noteBenefit

Who this is about

people practising hatha yoga pranayama

The tradition's frame

Yoga

In hatha yoga, restraining the breath (kumbhaka) restrains prana; when the energy channels (nadis) are purified by correct breath restraint, the breath enters the central channel (sushumna), and a still breath is held to bring a still mind and lead towards raja yoga.

Practical note

This records what the tradition holds, not a trial-established outcome. Research protocols often differ from the traditional texts in how breathing and holding are specified, which makes trial results hard to compare with traditional practice.

Vegan note

Not diet-related; applies equally to people following a vegan diet.

Safety note

Breath retention should never be practised in or near water, including baths and ice baths, because holding the breath after fast or deep breathing can cause sudden loss of consciousness. People who are pregnant or living with heart, lung or mental-health conditions are generally advised to check with a health professional before taking up breath-holding practices.

Sources

Supports “As long as the breath is restrained in the body, the mind is calm. As long as the gaze is between the eyebrows there is no danger of death. When all the channels have been purified by correctly performing restraints of the breath, the wind easily pierces and enters the aperture of the Sushumna.” (Section quoting Hatha Yoga Pradipika chapter 2 (Mallinson and Singleton translation)) Wikipedia contributors. Wikipedia. Hatha Yoga Pradipika. CC BY-SA 4.0; credit Wikipedia contributors
Context “We compared the specifications for posture, time of day, location, and duration of practice; frequency, depth, and holding (kumbhaka) of the breath;” (Abstract) Chetry D, Telles S, Mahadevan J, Prasoon K, Gandharva K, Agrawal M, Balkrishna A. 2022. International Journal of Yoga Therapy. A Comparison of Practice Guidelines for Yoga Breathing from the Traditional Texts and PubMed-Indexed Research. publisher copyright; metadata and short quotes only; Courtesy of the U.S. National Library of Medicine