Benefits of holding your breath, and the claims that fail

The three that hold up

Three effects of breath holding survive the evidence: the diving response, splenic contraction, and familiarity with the urge to breathe. Higher lung capacity, cured conditions and a named percentage gain in a fixed number of weeks do not. Every claim below carries its source. The fourth section covers paced breathing, which is a different practice.

Is holding your breath good for you?

For most healthy adults, dry breath holding is a low-risk practice with modest, well-bounded effects. The conditions carry the answer. In water without a trained buddy it is the most dangerous activity described on this page, and hyperventilating first makes a hold more dangerous rather than longer. Ask a clinician before you start if you have a heart, lung or neurological condition, uncontrolled high blood pressure, a history of fainting, or are pregnant. None of the documented effects is something you can measure on yourself, so nobody can tell from the inside whether the practice is working.

What is well documented

The diving response

Breath holding, particularly with the face in cool water, triggers a set of oxygen-conserving responses: slowing of the heart rate, constriction of peripheral blood vessels, and increased catecholamine release. A review of the human diving response describes its likely purpose as conserving oxygen for the brain and heart.

The magnitude varies a great deal between people and between attempts. A stronger diving response is not a safety margin you can measure or rely on.

Splenic contraction

Repeated breath holds cause the spleen to contract and release stored red blood cells. In a study of spleen emptying during repeated apneas, participants with a spleen showed haematocrit rise of 6.4% and haemoglobin rise of 3.3% across five maximal apneas, and their breaking point moved later. Participants who had had their spleen removed showed neither change. A later study comparing apnea with rebreathing found the response is driven substantially by respiratory arrest itself, not only by low oxygen.

These are short-lived shifts that reversed within about ten minutes in the 2001 study. They are not the same thing as building more red blood cells long term.

Familiarity with the urge to breathe

Rising carbon dioxide contributes to the growing urge to breathe, alongside falling oxygen, lung volume, and respiratory-muscle activity, as described in a review of respiratory responses to a maximal apnoea. Repeated structured practice mainly changes how familiar and manageable those sensations feel.

Short structured breathing practice and mood

A randomised controlled trial of brief structured respiration practices compared three five-minute daily breathwork exercises, including box breathing, with mindfulness meditation over one month. Breathwork produced greater improvement in mood and a greater reduction in respiratory rate, with exhale-focused cyclic sighing performing best.

That trial studied short paced-breathing exercises in a general adult sample. It is not a study of apnea tables, and it does not show treatment of any diagnosed condition.

What the research does not support

Research on apnea training and sport performance is mixed and protocol-specific. A review of apnoea training and aerobic and anaerobic performance and a review of breath-holding in sports both report possible benefits for some outcomes while calling for better-defined protocols and more evidence.

Because of that, this site does not claim any of the following:

• A named percentage improvement in breath-hold time within a fixed number of weeks.
• Treatment or cure of anxiety, depression, insomnia, hypertension, or any other condition.
• Reliable increases in lung capacity, resting heart-rate variability, focus, reaction time, or long-term red blood cell production.
• A stated reduction in cortisol from breath holding.
• Better sleep quality as a predictable outcome of apnea training.
• That a stronger diving response makes underwater breath holding safe.

If you see a program promising any of these on a schedule, treat the promise as marketing rather than evidence.

Wim Hof breathing versus breath-hold training

The two are often filed together and they are not the same practice. The Wim Hof breathing phase is cyclic voluntary hyperventilation, roughly 30 to 40 rapid deep breaths followed by a retention at low lung volume, as described in a systematic review of the method. Freediving-style apnea training deliberately avoids hyperventilation.

The mechanism matters. Hyperventilating before a breath hold can delay the urge to breathe without preventing oxygen from falling, which increases the risk of loss of consciousness, as Divers Alert Network sets out. That is why a Wim Hof retention feels easier than an ordinary hold of the same length: the warning has been quietened, not the oxygen cost removed. Never use it in or near water, in a bath, while driving, or standing up.

On the research, the most cited study is Kox et al. (2014): twenty-four healthy men, twelve trained for ten days in meditation, the breathing technique and cold exposure, all then given intravenous endotoxin. The trained group showed higher plasma epinephrine, a faster rise in the anti-inflammatory cytokine IL-10, lower TNF-alpha, IL-6 and IL-8, and fewer flu-like symptoms. That is an acute effect in twelve trained people under an experimental challenge, not evidence that the method treats infection or any other condition. The 2023 systematic review concluded the method may provide some benefits while noting the underlying studies remain few and small.

Who tends to find it useful

Freedivers and spearfishers use structured tables as part of preparation supervised by an instructor. Surfers and water-sports athletes use dry practice to become calmer with breath-hold discomfort. Endurance and combat-sport athletes experiment with it, and that is where the sport literature sits: plausible, protocol-specific, and not yet settled.

If your goal is general stress management rather than diving, paced breathing patterns such as box breathing have more directly applicable evidence than maximal breath holds.

How to train without overreaching

Keep sessions repeatable rather than maximal. A CO2 table repeats a manageable hold while shortening recovery; the CO2 table generator can build a conservative one. Record what you completed and how it felt, change one variable at a time, and reduce the load when you are ill, short of sleep, or unusually tired.

Read the breath-hold safety guide before using a timer or table. Consult a doctor first if you have heart, lung, or neurological conditions, or are pregnant.

Sources

• Freediving Safety, Divers Alert Network
• Voluntary activation of the sympathetic nervous system and attenuation of the innate immune response in humans (Kox et al., PNAS 2014)
• Does the Wim Hof Method have a beneficial impact on physiological and psychological outcomes? A systematic review (PLOS ONE, 2023)
• Hypoxia in Breath-Hold Diving, Divers Alert Network
• The human diving response, its function, and its control (Foster & Sheel, 2005)
• Role of spleen emptying in prolonging apneas in humans (Schagatay et al., 2001)
• Splenic contraction and cardiovascular responses during apnea compared to rebreathing (2023)
• Respiratory system responses to a maximal apnoea
• Brief structured respiration practices enhance mood and reduce physiological arousal (Balban et al., 2023)
• Effects of apnoea training on aerobic and anaerobic performance
• The application of breath-holding in sports