Breathing through your nose during exercise is genuinely better for performance than breathing through your mouth. Nasal breathing triggers nitric oxide release, improves oxygen efficiency, and keeps your airways humidified and filtered. The problem is that a lot of people physically cannot nasal breathe above a moderate effort level, especially if there is any structural obstruction in the nasal passage. If that is you, it is worth understanding why the limitation exists and what you can do about it.
What Your Nose Actually Does During Exercise
Your nose is not just a passive tube for air. When you inhale through your nostrils, the incoming air gets warmed to close to body temperature, humidified, and filtered of particles before it reaches your lungs. That matters for respiratory health during training, particularly in cold or dry environments where mouth breathing leads to airways drying out and triggering bronchospasm in susceptible people.
The bigger performance factor is nitric oxide. The paranasal sinuses produce nitric oxide continuously, and nasal breathing carries it down into the lungs with each breath. Nitric oxide is a vasodilator. It widens the pulmonary blood vessels and improves the uptake of oxygen from the alveoli into the bloodstream. That is a direct performance advantage, and it disappears entirely when you switch to mouth breathing.
There is also the CO2 balance piece. Nasal breathing encourages a slower, more controlled breathing pattern that keeps blood CO2 levels appropriately elevated. This matters because of the Bohr effect: haemoglobin releases oxygen to your muscles more readily in the presence of higher CO2. Over-breathing through the mouth reduces CO2 too fast and paradoxically makes oxygen delivery to working muscles less efficient, even though you are moving more air volume.
Why So Many Athletes Default to Mouth Breathing
The short answer is that the nasal airway has a much smaller cross-section than the mouth. At rest, nasal resistance accounts for roughly 50 percent of total respiratory resistance. As breathing demand increases with exercise intensity, the nose becomes the bottleneck. For people with normal nasal anatomy, this is manageable up to moderate-to-high intensities. For people with any structural narrowing, the nose becomes restricting well before that point.
I played rugby for over ten years at senior club level. By the time I was in my late twenties, I had taken enough impacts to the face that my nose was in noticeably worse shape than it started. I saw an ENT specialist who referred me to a Consultant Otolaryngologist at a private hospital in Dublin. The recommendation was septorhinoplasty, procedure code 5975. Full correction under general anaesthetic.
I deferred it. I was not ready to take six months out of rugby for recovery. So I started looking at what I could do in the meantime, and eventually landed on external nasal dilators as the most practical option. I wrote up a longer version of that process in my piece on the best nasal strips for a deviated septum if the backstory is relevant to you.
How the Nasal Valve Becomes the Problem
The nasal valve is the narrowest segment of the nasal passage, located about a centimetre inside each nostril. It is formed by the junction of the nasal septum, the inferior turbinate, and the lateral nasal cartilage. Under normal breathing conditions it works fine. Under high inspiratory effort during intense exercise, the lateral walls can collapse inward, narrowing the opening further and dramatically increasing resistance.
If you have a deviated septum, one side of the nasal valve is already partially compromised. The deviation reduces the effective cross-section on one side, so the threshold for collapse is lower. The result is that you hit your nasal breathing limit sooner than an athlete with normal nasal anatomy. This is not a fitness issue. It is a structural one.
What Nasal Strips Do in an Exercise Context
An external nasal dilator strip works by applying a spring-like lifting force to the nasal sidewalls from outside the nose. This reduces collapse at the nasal valve and widens the effective airway opening. It does not change the septum and it does not address internal swelling caused by mucosal congestion. What it does is give you more usable airway space on the external side, which for many people is the primary limiting factor during exercise.
When I started wearing Ventriq Sport Nasal Strips during training sessions, the effect was not dramatic in the way that a good fitness adaptation feels. It was subtler than that. The breathing effort itself came down. I was not fighting the first few minutes of a hard run trying to force enough air through before eventually switching to mouth breathing. I could maintain nasal breathing further into the effort. That translated to less perceived exertion at the same pace, which over a full training session adds up.
Research backs this up. Studies on external nasal dilators during exercise consistently show reductions in nasal airway resistance. Some show improvements in perceived breathlessness and time to exhaustion, particularly in populations with baseline nasal obstruction. If your nose is already working well, the gains are modest. If there is any obstruction, the benefit is more meaningful. I have gone into more detail on the published evidence in my post on whether nasal strips improve athletic performance.
Training Your Body to Nasal Breathe
If you have spent years mouth breathing during exercise, nasal only breathing will feel restrictive at first. You will hit your aerobic ceiling sooner and your pace will drop. That is normal. The respiratory system adapts to the demand placed on it. Most people who commit to nasal breathing during training find their threshold rises noticeably within four to eight weeks as the diaphragm and supporting respiratory muscles strengthen and CO2 tolerance improves.
The practical approach is to start at a pace you can sustain with your mouth closed and build from there. Zone 2 training, where you are working aerobically but not at your limit, is the ideal place to begin. As weeks pass, the intensity you can hold while breathing nasally will increase. High intensity intervals will likely always require some mouth breathing at peak effort, and that is fine. The goal is to raise the floor, not eliminate mouth breathing entirely.
For athletes with nasal obstruction, strips used during these sessions can make the difference between being able to sustain nasal breathing at a useful training intensity and not. I used them consistently through my transition period and still use them for harder sessions. You can read more about the sport-specific benefits in this overview of nasal strip benefits for sport.
The Sleep and Recovery Connection
How you breathe at night matters as much as how you breathe during training. Growth hormone release, muscle repair, and nervous system recovery all happen predominantly during deep sleep. If nasal obstruction is causing partial airway blockage, snoring, or fragmented sleep, you are running a recovery deficit that compounds across every training week.
I noticed this connection before I fully understood it. My sleep was poor for years and I assumed it was just stress or volume of training. Once I started using Ventriq Sleep Nasal Strips at night, the quality of my sleep changed enough that I could feel the difference within a week. Waking up less, less dry mouth in the morning, feeling more rested. The sleep strips use a gentler adhesive designed for overnight wear rather than the stronger formulation needed to hold through sweat during sport.
If this is relevant to you, I have written specifically about sleeping better with a deviated septum and there is a full piece on using nasal strips for restful sleep. The breathing and recovery connection goes deeper than most people realise.
Practical Tips for Using Nasal Strips During Training
- Apply the strip to clean, dry skin before any sweat builds up. Even a small amount of moisture when you apply it will compromise the adhesive and it will peel off during the session.
- Position the strip across the widest part of the nasal bridge, spanning both sidewalls. Too high and it sits above the nasal valve and does little. Too low and it misses the structural support it needs to provide.
- Give yourself a few sessions to find the right position for your nose shape. The nasal bridge width varies significantly between people and a slightly adjusted placement can make a real difference to how effective the strip feels.
- For contact sport like rugby, strips hold well through normal play but a direct impact to the face will dislodge them. That is an acceptable trade-off. For the 60 or 70 minutes where nothing hits your nose, the benefit is real.
- Remove by wetting the skin lightly if needed. Peeling a strong adhesive strip off dry skin after a hard training session is not a pleasant experience.
Frequently Asked Questions
Is nasal breathing actually better than mouth breathing during exercise?
Yes, for most purposes. Nasal breathing produces nitric oxide for better oxygen uptake, warms and filters air, and supports healthier CO2 balance for more efficient oxygen delivery to muscles. The limitation is airway size, which is why nasal dilators are useful at higher intensities where nasal resistance becomes the bottleneck.
Can I train myself to nasal breathe at high intensity?
Yes, over time. Start at lower intensities with your mouth closed and build over four to eight weeks. The respiratory system adapts. Most people find their nasal breathing threshold rises significantly with consistent training. Athletes with structural nasal obstruction will benefit from wearing a nasal strip during these adaptation sessions.
Will nasal strips help if I have a deviated septum?
They can, yes. A nasal strip does not correct the deviation but it opens the external nasal passage enough to reduce the functional restriction. For people with mild to moderate deviation, the strips provide meaningful relief during exercise and sleep. For severe cases, surgical correction may eventually be the only full solution, but strips can bridge the gap for a long time. More on this in my post on nasal strips for deviated septum.
What is the difference between sport and sleep nasal strips?
Primarily the adhesive. Sport strips use a stronger adhesive designed to hold through sweat during training. Sleep strips use a gentler formulation that is kinder to skin for eight hours of overnight wear. The underlying mechanism is the same. I use Ventriq Sport during training and Ventriq Sleep at night.
Does nasal breathing help with anxiety during hard training sessions?
There is real evidence connecting nasal breathing with reduced stress responses and improved parasympathetic nervous system activation. Slower nasal breathing patterns lower the physiological arousal associated with intense exercise, which for some athletes makes hard sessions feel more controlled. I have written about this in more depth in my post on the surprising link between nasal obstruction and anxiety.
How long does it take to see results from nasal breathing training?
Most people notice changes within two to four weeks at the level of perceived effort. Measurable improvements in CO2 tolerance and the ability to sustain nasal breathing at higher intensities typically develop over four to eight weeks of consistent practice. The adaptation is real but it requires patience at the start when everything feels harder than it should.
If you want to try nasal breathing during training and get a proper assessment of whether a dilator strip would help your specific restriction, the best starting point is simply to test one session with and without a strip and pay attention to where your breathing starts to break down. The difference, if there is structural obstruction involved, tends to be obvious within a few minutes of hard effort.
You can pick up Ventriq Sport Nasal Strips for training and Ventriq Sleep Nasal Strips for overnight recovery. If you are carrying a deviated septum or any degree of nasal restriction, using both is the approach that made the biggest difference for me.
