Benefits of Breath-Hold Training: What the Evidence Actually Supports

Short answer

Breath-hold training reliably teaches you to recognise and stay calm with the discomfort of a breath hold, and it triggers well-documented short-term responses such as slowing of the heart rate and contraction of the spleen. It does not have good evidence behind promises of cured conditions, guaranteed performance gains, better sleep, higher lung capacity, or a fixed percentage improvement in a set number of weeks.

This page separates the two categories and links the source beside each claim.

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.

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
• 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