Ask most runners about their training and they'll talk shoes, mileage and heart-rate zones. Almost nobody talks about the first piece of equipment every breath passes through: the nose. That's a missed opportunity, because how you breathe changes how running feels.
What your nose actually does when you run
Breathing through your nose isn't just an alternative intake route. Compared to mouth breathing, nasal breathing:
- Filters, warms and humidifies air before it reaches your lungs — which is why cold, dry air feels harsher through the mouth.
- Produces nitric oxide in the nasal passages, a molecule that helps dilate blood vessels and may improve oxygen uptake in the lungs.
- Encourages slower, deeper diaphragmatic breaths rather than shallow upper-chest panting.
The catch: the nose is a narrow pipe
The limiting factor is resistance. The nasal valve which is the narrowest slot in your airway restricts how much air you can pull in, and it actually tends to collapse inward slightly when you inhale hard. That's exactly what happens during a tempo run or hill repeats. Many runners abandon nasal breathing not because it doesn't work, but because their nose physically can't keep up at intensity.
Where nasal strips come in
An external nasal dilator strip mechanically pulls the nasal valve open and holds it there, increasing airflow through the nose and preventing that inward collapse on hard inhales. In practical terms, it raises the intensity ceiling at which nasal breathing stays comfortable. Studies on nasal dilators consistently show reduced nasal resistance; for athletes, the most reliable benefit is subjective — breathing feels noticeably easier — which matters, because perceived effort is a real limiter in endurance sport.
To be straight with you: research hasn't shown that nasal strips directly increase VO2 max. What they change is the airflow bottleneck at the nose, making relaxed nasal breathing sustainable at paces where you'd otherwise switch to gasping through your mouth.
How to train nasal breathing as a runner
- Start on easy runs. Keep your mouth closed on your recovery runs. If you can't, you're running too fast — which is useful zone-2 feedback in itself.
- Use a strip from day one. Lowering nasal resistance makes the adaptation phase far less frustrating.
- Expect a 3–6 week adjustment. Your CO2 tolerance and breathing mechanics adapt; what feels restrictive in week one feels natural by week four.
- Let intensity decide. At race pace or in intervals, breathe however moves the most air. Nasal breathing is a training tool, not a rule.
Recovery counts too
Adaptation happens when you sleep. Wearing a nasal strip at night supports easier nasal breathing while you rest — many athletes notice less mouth dryness and deeper-feeling sleep. If you also snore, there's a bonus in it for you: see our guide on whether nasal strips help with snoring.
The bottom line
Your nose is trainable equipment. Combine gradual nasal-breathing practice with a strip that keeps the airway open, and easy runs get calmer, cold air gets kinder, and your breathing stops being the loudest thing on the trail. Gee nasal strips are built for exactly this — medical-grade adhesive that stays put through sweat, with designs you'll actually want to wear. See the lineup.