Closed mouth, nasal breathing and endurance
When the image disturbs old assumptions
We are seeing more and more images that disturb old ways of reading endurance sport: a marathon runner finishing at astonishing speed with a relatively relaxed face, a World Tour cyclist crossing the line with a closed mouth, an athlete able to sustain a huge intensity without displaying the classic image of a body in visible distress.
Very quickly, certain comments appear: "that is not normal", "he is not suffering", "that is suspicious", "that is cheating". I think we need to be much more serious than that.
What the image does not say
A closed mouth at the finish line does not tell us precisely what is happening inside the body. The athlete may have used nasal breathing during some phases, alternated nasal and oronasal breathing, closed the mouth at the finish, or simply displayed a highly relaxed facial expression.
From a single image, we cannot conclude. And that is exactly the central point: if the image does not prove exclusive nasal breathing, it does not prove cheating either.
Accusing an athlete of doping based on what we think we see, what we think we recognise, or what we imagine should be "normal" is a dangerous drift. It turns an impression into a conviction.
Modern endurance cannot be read only with old codes
For a long time, maximum effort was associated with a simple image: open mouth, distorted face, loud breathing, visible struggle. But today's best athletes are not only trying to produce more. They are also trying to waste less.
Less wasted energy, less tension, fewer parasitic movements, less ventilatory disorganisation, less useless stress in the system. Modern performance has become a science of economy.
Running economy, pedalling economy, ventilatory economy, gestural economy, nervous-system economy: what we see at the finish line is not only the product of an exceptional engine. It is also the result of a system that has learned to remain organised under constraint.
The two-hour marathon barrier: a symbol of complexity
The sub-two-hour marathon is a powerful example. For decades, that barrier seemed impossible. Then it became approachable, was broken under optimised conditions, and was eventually broken officially in a race.
When two athletes run under two hours on the same day, of course it raises questions. But that question can go in two directions. The poor one is: "it is impossible, so they are cheating". The more interesting one is: what have we understood more deeply about training, physiology, nutrition, equipment, strategy, recovery and human economy to make this possible?
This second question does not exclude anti-doping vigilance. It simply refuses to reduce human performance to chemistry. A banned product alone does not build running economy, nutritional strategy, adapted respiratory capacity, or an athlete able to maintain exceptional organisation for two hours.
The nose is not a decorative organ
In this debate, nasal breathing deserves a real place: not as a trend, not as a miracle recipe, not as proof of superiority, but as a trainable physiological capacity.
The nose is not merely an air inlet. It is a specialised respiratory pathway. It filters, humidifies, warms and conditions inspired air. The paranasal sinuses are also involved in the production of nitric oxide, which is implicated in several local airway mechanisms.
Breathing through the nose does not automatically make anyone run faster. But we should stop reducing the nose to a simple anatomical accessory. In a non-adapted person, nasal restriction may trigger a feeling of air hunger. In a progressively trained endurance athlete, it may become a tool for regulation and adaptation.
What the science says, without exaggeration
Available studies do not allow us to claim that nasal breathing automatically improves performance. That would be false. However, they suggest something more subtle: some adapted individuals can maintain nasal breathing at higher intensities than previously assumed, sometimes without major loss of maximal performance, and with interesting changes in ventilatory economy.
The balanced position avoids two extremes: saying that nasal breathing is useless, or saying that it is magical. Nasal breathing is a skill. A skill can be trained, depends on context, and may become an additional margin.
What I observe in clinic: stress often breathes through the mouth
This reflection does not come only from elite sport. It also comes from clinical practice.
For several years, I have observed something striking in people arriving with high levels of stress: they very often breathe through the mouth. They speak and breathe at the same time, as if they were short of air. The mouth remains slightly open, the breath is high, the thorax seems to search for air, the face is tense and the shoulders participate too much.
This is not a scientific study. It is a personal clinical observation. But it has appeared frequently enough to raise a real question: what happens when a stressed system progressively loses calm access to nasal breathing?
When I suggested simple seated nasal-breathing exercises to some patients, sometimes within a cardiac coherence framework, the reaction was immediate: discomfort, agitation, air hunger, tension, sometimes almost panic. It was not only a technical difficulty. It was a maladaptation.
Stress, open mouth and loss of margin
In the stressed patient, mouth breathing may be the sign of a system on alert. The body seeks air quickly, breathes higher, tolerates slowing less easily and struggles with nasal restriction.
In the endurance athlete, by contrast, progressively training nasal breathing may increase tolerance to a constraint. The system learns to remain calm with a narrower airflow pathway. It learns not to panic. It learns to organise the breath instead of being dominated by it.
The osteopathic interest
Osteopathy can bring an interesting perspective, provided it remains serious. The osteopath should not promise to turn nasal breathing into a direct performance advantage. However, the osteopath can observe where the body is losing availability.
Breathing is not merely about bringing air in. It involves mobilising the rib cage, allowing the ribs to move, letting the diaphragm work, organising the spine, relaxing the cervical area, freeing the jaw, softening the throat and creating space around the larynx, pharynx, tongue and upper airway.
The role of the osteopath is not to impose an ideal breath. The role is to restore options: more thoracic mobility, more diaphragmatic suppleness, more cervical release, more freedom around the throat, more nasal availability and more autonomic margin.
A Bioterreno reading: breathing as an indicator of terrain
In a Bioterreno reading, breathing is not an isolated gesture. It is an indicator of the terrain.
The same breathing exercise does not produce the same response in two different people. For one, slow nasal breathing calms the system. For another, it triggers a feeling of suffocation. The difference is not only in the exercise. It is in the state of the system when the constraint arrives.
How to train it without falling into dogma
For athletes, the goal is not to run or ride always with the mouth closed. At high intensity, oronasal breathing often becomes necessary. The mouth also has a role: the body seeks the airflow it needs.
Nasal breathing can be progressively trained at easy intensities: active walking, slow running, low-intensity cycling, warm-up, cool-down and active recovery.
At first, discomfort may appear. That is normal. The constraint must remain low. The goal is not to fight air hunger, but to teach the system that it can breathe differently without going into alert.
Three levels of reading
This article distinguishes three levels: published evidence, personal clinical observation, and professional interpretation drawn from osteopathy and the Bioterreno approach.
This document is a professional reflection article. It is not individual medical advice, not an accusation, and not a blind defence of elite sport.
What this article raises
Learning to read the living body better
A closed mouth at the finish line does not prove exclusive nasal breathing. But it does not prove cheating either.
It may be a simple image, a moment, an expression of relaxation. It may also open a deeper question: how far can the human body be trained to remain organised under constraint?
Nasal breathing is not a miracle solution. It is an adaptive capacity: a capacity that can be lost under stress, rebuilt in clinical work and trained in athletes.
The nose is not a decorative organ. Breathing is not a detail. Relaxation is not proof of cheating. And human performance does not deserve to be reduced to suspicion.
Sometimes, a body that holds together is not hiding fraud. Sometimes it simply reveals a level of adaptation that we do not yet know how to read well. Perhaps that is the real challenge today: learning to read the living body better.
Sources and references
World Athletics. TCS London Marathon 2026 results and report: Sabastian Sawe 1:59:30, Yomif Kejelcha 1:59:41. https://worldathletics.org/competitions/world-athletics-label-road-races/calendar-results/7235562/result
World Athletics. Sawe breaks two-hour barrier with 1:59:30 world record at London Marathon. https://worldathletics.org/competitions/world-athletics-label-road-races/news/sawe-two-hour-assefa-world-record-london-marathon
Dallam GM, McClaran SR, Cox DG, Foust CP. Effect of Nasal Versus Oral Breathing on VO2max and Physiological Economy in Recreational Runners Following an Extended Period Spent Using Nasally Restricted Breathing. International Journal of Kinesiology and Sports Science. 2018.
Dallam GM, Kies B. The Effect of Nasal Breathing Versus Oral and Oronasal Breathing During Exercise: A Review. Journal of Sports Research. 2020.
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Rappelt L et al. Restricted Nasal-Only Breathing During Self-Selected Low Intensity Training Does Not Affect Training Intensity Distribution. Frontiers in Physiology. 2023.
Bergqvist J et al. Effects of oral, oronasal, and oronasal breathing with a decongested nose during incremental maximal exercise testing of well-trained endurance athletes. Frontiers in Physiology. 2025.
Lundberg JO. Nitric oxide and the paranasal sinuses. Anatomy and physiology of the nose and paranasal sinuses. 2008.
Cleveland Clinic. Hyperventilation Syndrome: Symptoms, Causes and Treatment. https://my.clevelandclinic.org/health/diseases/24860-hyperventilation-syndrome
University Hospital Southampton NHS Foundation Trust. Breathing pattern disorders - patient information.
