Running is funny. We will spend years building a better aerobic engine, grinding out hill reps in sideways rain, sacrificing sleep, toenails and bits of dignity, only to then let some bloke on Instagram tell us the missing piece was taping our mouth shut and jogging around looking like a suburban Batman villain.
Breathing has become one of those topics where genuine physiology gets mugged in a dark alley by internet fads. Somewhere between “just breathe through your nose, bro” and “buy this altitude mask and unlock your ancestral lung code,” the whole thing has wandered off into the weeds.
So let’s drag it back.
There is real research around breathing and running. Some of it is useful. Some of it is interesting but not especially actionable. Some of it has been dressed up in activewear and sold back to athletes like a steaming bag of enchanted rubbish. The short version is that breathing matters, but not in the mystical, guru-led, moon-cycle nonsense way some corners of the internet would have you believe. It matters because breathing has a real mechanical cost, a real metabolic cost, and under hard exercise your respiratory muscles can become one more set of tissues fighting for blood flow with the legs. That is not airy fairy breathwork nonsense. That is actual physiology.
An early study showed that respiratory muscle fatigue can occur during heavy exercise and can reduce performance through increased work of breathing and competition for blood flow with locomotor muscles.
A later meta analysis that respiratory muscle training can improve endurance performance, especially in longer duration exercise and in less highly trained individuals. (pubmed.ncbi.nlm.nih.gov)
That point matters because it gives us the first clean distinction. Breathing is not irrelevant. But neither is it magic. If your breathing is a mess, it can matter. If your breathing is normal, relaxed and fit for purpose, you probably do not need to reinvent your entire identity around your nostrils.
Let’s start with the old chestnut about “breathing from the diaphragm.” This gets thrown around so often it has become the running equivalent of “engage your core,” which is another phrase that can mean something useful or absolutely bloody nothing depending on who is saying it. The diaphragm is the primary muscle of breathing. That part is not controversial. What people usually mean is that runners should avoid shallow, frantic, upper chest breathing that looks like a squirrel having an existential crisis in traffic.
And that part is fair enough.
Where people get this wrong is in turning a sensible mechanical principle into a religion. You do not need to force absurdly exaggerated belly breathing while running hard. At easy paces, calm and low tension breathing makes sense. At moderate and hard paces, breathing gets bigger and faster. That is not dysfunction. That is your body doing its job. Trying to hold onto some pristine yoga class diaphragm ideal while you are up to your eyeballs at threshold is like insisting on using a salad fork during a bar fight. Technically elegant, perhaps. Totally missing the point.
Then there is the question of rhythm. Should your breathing sync with your stride? Is there some sacred 3:3 pattern carved into a stone tablet on a mountain somewhere?
Rhythm can be a cue. It can help settle an athlete. It can help stop them from running like an excited Labrador on laminate flooring. Easy running often lands naturally into something like 3:3 or 4:4. Threshold work may drift toward 2:2. Harder efforts can become 2:1 or more chaotic. Fine. Let it happen. But forcing every runner into some rigid pattern because an influencer with a beige hat said it “balances energy” is silly. The research supports coupling as a natural phenomenon. It does not support one universal stride-breathing commandment.
Now for the nose breathing crowd, who have emerged from the internet swamp in linen shorts to tell us all that mouth breathing is essentially moral failure.
Nasal breathing does have legitimate advantages. The nose warms, filters and humidifies air better than the mouth. There may be circumstances where that matters, especially for athletes with airway sensitivity. But the idea that nasal only breathing is the superior default for all running is not supported in any strong universal sense.
That is the key. Nasal breathing can be a tool. It can be useful in warm ups, easy aerobic running, recovery runs, or in athletes who overbreathe and need to calm the circus down a bit. But the idea that you should be charging threshold reps through the nose because your ancestors once chased antelope that way is complete farmyard theatre. The body is not stupid. When intensity rises, it recruits more airflow. That is why the mouth exists. Mouth breathing at hard effort is not failure. It is not weakness. It is not a sign your chakras are leaking. It is biology.
Which brings us neatly to nasal strips, those little adhesive moustaches of false hope stuck across the face of modern sport like some kind of aerodynamic clown plaster.
The science here is not exactly kind. A systematic review and meta analysis found that external nasal dilator strips did not improve VO2max, heart rate, or rating of perceived exertion during exercise in healthy individuals.
That does not mean nobody gets subjective benefit. Placebo is real. Comfort is real. Ritual is real. Athletes are weird creatures and sometimes weird creatures like weird things. But there is a huge difference between “I like wearing this” and “this is a science backed endurance breakthrough.” One is personal preference. The other is marketing in activewear.
And then we arrive at the final boss of breathing nonsense: the fake altitude mask. The Darth Vader mask. The wheezy plastic face hugger sold to athletes as if it contains the spirit of Kilian Jornet and a small pocket of the Bolivian highlands.
These things are marketed as altitude simulators. Most of them are not.
Real altitude training works by reducing inspired oxygen pressure. That changes the oxygen available to the body. Most commercial elevation masks do not do that in any meaningful way. What they mainly do is increase airflow resistance. That makes breathing feel harder. Which is not the same thing at all. It is the difference between climbing an actual mountain and breathing through your cousin’s vacuum cleaner attachment.
The research supports this distinction. Commercial respiratory interventions make claims well beyond what the literature can support.
Do not sell it as alpine wizardry. Do not dress up a resistance gadget in altitude drag. That is like painting a donkey silver and telling people you’ve invented a horse from space.
If you want the one breathing intervention that has actual respectable evidence behind it, it is respiratory muscle training. Actual inspiratory muscle training.
Respiratory muscle training has been studied in athletes and healthy individuals and generally shows modest but meaningful benefits in endurance performance, particularly for longer events and in less trained populations. There is also evidence that it may reduce the respiratory muscle ‘metaboreflex’, which is the elegant bit of physiology where tired breathing muscles start contributing to sympathetic activation and blood flow redistribution away from the limbs. That is a very real mechanism, and exactly the sort of thing that matters when athletes are breathing like an overheated tractor halfway through a hard session or long race. (PubMed)
So yes, breathing can be trained. But the trainable bit is not usually some elaborate performance art around whether your tongue rests on the roof of your mouth while Mercury is in retrograde. It is about mechanical efficiency, respiratory muscle function, and not turning an automatic biological process into an anxious hobby.
Importantly, some athletes do have genuine breathing issues.
Exercise induced laryngeal obstruction, for example, is increasingly recognised in athletes and can mimic asthma. It can present as throat tightness, inspiratory noise, chest tightness, and distress during hard exercise. More on EILO here.
Dysfunctional breathing patterns can also exist alongside otherwise healthy lungs.
If you consistently report unusual breathing distress, wheeze, throat closure, panic or noisy inhalation at intensity, get properly assessed.
At the end of the day – At easy paces, relaxed diaphragmatic dominant breathing makes sense. At harder paces, let breathing expand naturally and use the mouth when needed.
Rhythm can be useful, but it is a cue, not scripture. Nasal strips have no shown benefit. So-called ‘altitude masks’ do not turn your local bike path into the Tibetan plateau. Respiratory muscle training is the one intervention here with proper legs.
If breathing feels genuinely wrong, unusual or limiting, get the athlete assessed instead of sending them deeper into the influencer sewer.
And as with so much in endurance sport, the boring answer wins again.
Train well. Breathe normally. Be suspicious of gadgets.
Especially the ones that make you look like a sex pest version of Darth Vader.
