Breathing Exercises for Swimming

Breathing exercises on dry land are one of the most under-used tools in competitive swimming. Research suggests they can improve breathing control, strengthen the breathing muscles and help manage exercise-induced asthma, and some studies report gains in swimming performance. This article explains which exercises to use, what the research does and doesn't show, and why you should never practise breath holds in the water.

As a competitive swimmer, you want to know how to swim faster. Your focus might be technique or strength training, but the end point is the same. In competitive swimming, better IS faster.

Yet many swimmers have yet to tap into breathing exercises, even though a growing body of research supports their role in breathing control, respiratory muscle strength and airway health.

How Breathing Affects Swimming Speed and Performance

The basic principles of fast swimming focus on technique:

• Optimising your body position in the water
• Refining your kick
• Focusing on your arm movement and stroke technique
• Improving swimming coordination
• Reducing drag

Breathing affects every one of these. Each breath can disrupt body position and stroke rhythm, and inefficient breathing adds to the work your breathing muscles have to do.

Think quality, not quantity. Swimming workouts to build speed should not include "garbage yardage." Piling on volume without purpose raises the risk of shoulder injury, persistent fatigue and performance plateaus.

A dry land breathing protocol is a practical way to train an often-overlooked part of performance without adding more pool volume.

Dryland Breathing Training for Swimmers: What the Evidence Shows

Dryland training for swimmers involves stretching and strengthening the arms, legs and core. It improves form in the water and helps protect against injury. It supports balance, posture, alignment and movement, leading to better all-round swim technique.

But the missing link in most programmes is a dry land protocol of breathing exercises.

Breathing Exercises for Swimmers on Dry Land

Breathwork training on dry land is not yet commonplace among swimmers, despite growing research interest.

It includes breathing exercises to strengthen the breathing muscles, which may help delay respiratory muscle fatigue. Nasal breathing during dryland work supports airway health. It does not need much extra training time, and research on inspiratory muscle warm-ups suggests benefits for some athletes even when breathing work is used only as part of a warm-up (Cirino et al., 2023).

Breath holding on dry land is another tool. Holding the breath after an exhalation lowers blood oxygen (hypoxia) and raises carbon dioxide (hypercapnia), a stimulus sometimes compared to altitude training. It also produces strong air hunger, giving swimmers controlled practice at staying calm and in control while the urge to breathe builds.

Why You Should Never Practise Breath Holds in the Water

There are many advanced ways to control your breathing in the water. But practising breath holds while swimming or underwater is never a good idea.

Strong, confident young swimmers have died practising breath holds in the pool. A 2015 report from the US Centers for Disease Control and Prevention (CDC) reviewed 16 cases of dangerous underwater breath-holding in New York State between 1988 and 2011. All four people who died were aged 17 to 22, were advanced to expert swimmers, and had used intentional hyperventilation (Boyd et al., 2015).

The review was prompted by a 2011 incident in which two healthy young men died at a regulated New York City pool, where lifeguards were on duty. Both became unconscious underwater after hyperventilating before submerging. Another case involved a teenage swimmer training to join the US Navy SEALs, who repeatedly submerged for long periods until he lost consciousness.

In some breathwork methods, hyperventilation is performed before breath holding to lower CO₂ levels in the blood. This prolongs the breath hold, but it is dangerous. During a breath hold, the cells continue to extract oxygen from the blood.

With CO₂ lowered, the urge to breathe can arrive too late. Oxygen can fall to dangerously low levels before you feel the need to surface. The result can be hypoxic blackout, often called shallow water blackout.

What Is Shallow Water Blackout and Why Is It Dangerous?

• Hyperventilation means breathing more than the body needs. This lowers CO₂ levels in the blood.
• During a breath hold, blood oxygen levels fall (hypoxia).
• Normally, rising CO₂ is an important contributor to the urge to breathe, prompting you to surface.
• If you hyperventilate before breath holding, CO₂ starts so low that the urge to breathe may not arrive in time.
• Combined with low oxygen, this can cause sudden unconsciousness, often without warning.
• Once you have blacked out, your body eventually initiates a breath. If you are underwater, you inhale water and can drown unless immediately rescued.
• Anyone who has lost consciousness in the water or inhaled water needs medical assessment, even if they seem fine, because breathing problems can develop in the hours afterwards.
• The best advice, no matter your skill level, is never to practise breath holds in the water.
• The Oxygen Advantage method does not use hyperventilation. Even so, keep your breath holds out of the pool.

Breath holding on dry land, practised correctly, is a far safer way to train your breathing for the pool.

How Dry Land Breath Training Supports Swimming Performance

Your swimming training programme can include a dry land breathing protocol built on two pillars: functional everyday breathing and intermittent hypoxic/hypercapnic training (IHHT).

Different exercises train different parts of the breathing system. Nasal breathing and light, slow breathing train breathing pattern and control. Breath holds after exhalation create a larger change in blood gases and a stronger air hunger. Resistance breathing trains the breathing muscles.

Functional Breathing Exercises for Swimmers

• Breathe through your nose during dryland training. Nose breathing warms and humidifies the air, and research shows it can reduce symptoms of exercise-induced asthma compared with mouth breathing (Shturman-Ellstein et al., 1978; Mangla and Menon, 1981). Asthma and exercise-induced bronchoconstriction are common in competitive swimmers.
• Nasal breathing adds resistance to airflow. This slows the breath, adds a load to the breathing muscles and encourages the diaphragm to engage.
• Good diaphragm function contributes to core stability, which supports body position in the water.
• Light, slow nasal breathing after training helps settle breathing and heart rate, supporting recovery.

Mouth breathing is normal during swimming, and nasal breathing on land works best at low to moderate intensities. At maximal effort, exclusive nasal breathing limits how much air you can move (Mapelli et al., 2025). Even when you breathe through your mouth in the pool, breathing efficiency and control still matter.

You can track your breathing with the BOLT score test. BOLT measures how quickly you feel the first clear urge to breathe during a comfortable breath hold after a normal exhalation. It is influenced by several factors, including chemical sensitivity, starting blood gases, breathing pattern, respiratory sensation, lung volume and psychological state.

BOLT is useful as a personal baseline to track your progress, but it is not a diagnostic test and it does not predict athletic performance. A 2024 study using the Oxygen Advantage BOLT protocol in 49 highly trained speed skaters found no relationship between BOLT and VO₂max or anaerobic test performance (Kowalski et al., 2024).

Is Hypoxic Training Good for Swimmers?

"Hypoxic training" has a long history in swimming. Coach James Counsilman popularised sets where swimmers breathe less often, for example every 7 or 9 strokes, mainly to reduce breathing frequency, improve stroke rhythm and build breathing control under pressure.

Breath holds after an inhalation, as happens in the water, mainly raise CO₂ and cause only a modest drop in blood oxygen. On dry land, breath holds after an exhalation produce a much larger drop in oxygen alongside the rise in CO₂. They can be practised while walking or jogging, with no risk of drowning.

Dry land IHHT provides several training stimuli:

• Respiratory muscle load: one study found that dry land breath-hold training increased respiratory muscle strength in elite swimmers (Karaula et al., 2016).
• Exposure to strong air hunger: repeated, controlled practice may change how you perceive and respond to the urge to breathe, helping you stay calm and in control. It is less clear how much it changes chemical sensitivity to CO₂.
• Blood changes: some studies report changes in haemoglobin after breath-hold training, although the evidence is limited and not consistent across studies.

Some studies report improvements in swimming performance, but results depend on the programme and the athletes, and breathing is only one part of what makes you faster.

To learn more about the research on breath holding and EPO and red blood cell production, read our full guide.

Note: Strong breath holds are powerful and not suitable for everyone. Avoid them if you have heart disease, high or low blood pressure, epilepsy, diabetes, pulmonary hypertension, uncontrolled asthma, a history of fainting, or any serious medical condition, or if you are pregnant, unless cleared by your doctor. Children should only practise gentle versions under supervision. If possible, learn the exercises with a certified Oxygen Advantage® instructor.

Research: Breathing Exercises and Swimming Performance

The studies below are small, and several were carried out in the water under close laboratory supervision. They should not be copied in the pool. Oxygen Advantage breath-hold training is done on dry land only.

Study 1: Apnea Training and Swimming Coordination

French researchers tested four male swimmers before and after a three-month breath-hold training programme. After training, the swimmers had a higher forced expiratory volume (how much air they could exhale in one second) and improvements in several measures during a maximal cycling test.

During a 50 m sprint, their stroke organisation was less disturbed, fatigue appeared later, and they showed greater continuity between the propulsive phases of the two arms. The researchers concluded that apnea training may improve effectiveness at peak and submaximal exercise and support swimming technique. With only four participants, these findings need confirming in larger studies.

Lemaître F, Seifert L, Polin D, Juge J, Tourny-Chollet C, Chollet D. Apnea training effects on swimming coordination. J Strength Cond Res. 2009 Sep;23(6):1909-14.

Study 2: Breath-Hold Experience and Breathlessness

Lemaître and colleagues compared the responses of trained underwater hockey players and untrained men to five short breath holds with the face immersed, spaced five minutes apart. Twenty men took part.

The underwater hockey players reported less breathlessness and had higher CO₂ levels in their exhaled breath after the test. Because the study compared two different groups rather than training one group over time, it shows an association with breath-hold experience, not proof that breath-hold practice caused the difference.

Lemaître F, Polin D, Joulia F, et al. Physiological responses to repeated apneas in underwater hockey players and controls. Undersea Hyperb Med. 2007 Nov-Dec;34(6):407-14.

Study 3: Creating Hypoxia at Sea Level Through Voluntary Hypoventilation

This laboratory study investigated whether swimmers can train under hypoxic conditions through voluntary hypoventilation, a controlled form of reduced breathing. Ten trained swimmers performed a front crawl series with normal breathing and with reduced breathing at high and low lung volume.

Reduced breathing at low lung volume (after exhaling) caused a large drop in blood oxygen saturation and increased reliance on anaerobic energy, while reduced breathing at high lung volume did not produce the same effect.

Woorons X, Gamelin FX, Lamberto C, Pichon A, Richalet JP. Swimmers can train in hypoxia at sea level through voluntary hypoventilation. Respir Physiol Neurobiol. 2014 Jan 1;190:33-9.

Study 4: Hypoventilation Training and 100 m, 200 m and 400 m Times

Over five weeks, sixteen triathletes added one supramaximal set of 12 to 20 × 25 m front crawl to their usual swimming session twice a week. Half performed the set with reduced breathing at low lung volume, and half with normal breathing. The sessions were carefully supervised.

Times improved significantly in the reduced-breathing group: by 4.4% over 100 m, 3.6% over 200 m and 3.5% over 400 m. The control group did not improve. VO₂max did not change in either group. The researchers linked the gains partly to increased anaerobic energy production.

Woorons X, Mucci P, Richalet JP, Pichon A. Hypoventilation Training at Supramaximal Intensity Improves Swimming Performance. Med Sci Sports Exerc. 2016 Jun;48(6):1119-28.

Study 5: Dry Land Breath-Hold Training in Elite Swimmers

Twenty-six elite male Croatian swimmers followed the same swimming programme for eight weeks. The experimental group also performed breath holds while running on a treadmill, on dry land, three times a week.

Compared with the control group, the breath-hold group showed significantly greater gains in inspiratory and expiratory muscle strength, took fewer breaths during a 100 m front crawl swim, and improved their 100 m time by 3.6%, compared with 1.1% in the control group.

Karaula D, Homolak J, Leko G. Effects of hypercapnic-hypoxic training on respiratory muscle strength and front crawl stroke performance among elite swimmers. Turkish Journal of Sport and Exercise. 2016;18(1):17-24.

Study 6: Hypercapnic-Hypoxic Training, Haemoglobin and VO₂max

A study by the same Croatian research group reported significant increases in haemoglobin concentration and VO₂ max in elite swimmers who practised breath holding after an exhalation. This was a small study, and other research has not always found changes in VO₂max, so the result should be treated with caution.

Zoretic D, Grcic-Zubcevic N, Zubcic K. The Effects of Hypercapnic-Hypoxic Training Program on Hemoglobin Concentration and Maximum Oxygen Uptake of Elite Swimmers. Kinesiology. 2014;46(Suppl 1):40-45.

If you are interested in trying the OA method for yourself, why not try our online course, become a certified breathwork instructor, or find an Oxygen Advantage® instructor near you.

FAQs

Q: How should competitive swimmers train their breathing?
A: Combine nasal breathing during dryland work and rest, light and slow breathing for recovery, and dry land breath holds after exhalation during walking or jogging. Swimming coaches also use reduced-breathing sets, such as breathing every 3, 5 or 7 strokes, to build rhythm and control. These should stay submaximal and supervised, and should never involve hyperventilation, long underwater swims or maximal breath holds.

Q: What are the best breathing exercises for swimmers out of the water?
A: Useful out-of-water exercises include Breathe Light to reduce breathing volume, dynamic breath holds during walking or jogging, and resistance breathing using the OA SportsMask. Together they train breathing control, your response to air hunger and respiratory muscle strength. Keep all breath holds on dry land.

Q: How does CO₂ tolerance training help swimmers?
A: In Oxygen Advantage, CO₂ tolerance is a practical training term for staying comfortable and in control as air hunger builds. Training this can help swimmers stay calm, keep their technique and manage breathlessness under pressure. It is not the same as a laboratory measure of CO₂ sensitivity, and the exact mechanism is still being researched.

Q: Is hypoxic training safe for swimmers?
A: Only on dry land, and only for people without relevant medical conditions. Breath holds should never be practised in or under water because of the risk of hypoxic blackout and drowning. If you have a heart condition, high or low blood pressure, epilepsy or another serious condition, check with your doctor first.

Q: Can breathing exercises improve recovery between swimming sets?
A: Slow, light nasal breathing after hard efforts can help settle breathing and heart rate and shift the nervous system toward recovery. Many swimmers find it helps them feel calmer and more focused between sets. Research specific to recovery in swimming is still limited.

References

1. Boyd C, Levy A, McProud T, Huang L, Raneses E, Olson C. Fatal and nonfatal drowning outcomes related to dangerous underwater breath-holding behaviors: New York State, 1988–2011. Morbidity and Mortality Weekly Report. 2015;64(19).
2. Cirino C, Marostegan AB, Hartz CS, Moreno MA, Gobatto CA, Manchado-Gobatto FB. Effects of inspiratory muscle warm-up on physical exercise: a systematic review. Biology (Basel). 2023;12(2):333.
3. Kowalski T, Rębiś K, Wilk A, et al. Body Oxygen Level Test (BOLT) is not associated with exercise performance in highly-trained individuals. Frontiers in Physiology. 2024;15:1430837.
4. Mangla PK, Menon MPS. Effect of nasal and oral breathing on exercise-induced asthma. Clinical Allergy. 1981;11(5):433–439.
5. Mapelli M, et al. Nasal vs. oral BREATHing WIn Strategies in healthy individuals during cardiorespiratory Exercise testing (BreathWISE). PLoS One. 2025;20(7):e0326661.
6. Shturman-Ellstein R, Zeballos RJ, Buckley JM, Souhrada JF. The beneficial effect of nasal breathing on exercise-induced bronchoconstriction. American Review of Respiratory Disease. 1978;118(1):65–73.