Does Nasal Breathing Improve Performance?

Some time ago, I started seeing this trend all over social media. Influencers were claiming nasal breathing had almost magical powers — from refining your jawline to boosting oxygen uptake. Honestly, I was skeptical. To me, breathing was just ventilation. What difference does it make whether the air goes in through the nose or the mouth?

Then, that same year, I met a guy at the gym who was absolutely frothing about it. "Elite athletes use it," he claimed. Really? I had to start digging.

What Does the Science Say?

One of the most comprehensive reviews so far is by Dallam & Kies (2020), titled "The Effect of Nasal Breathing Versus Oral and Oronasal Breathing During Exercise".

Here are some highlights:

Efficiency and Performance

• Nasal breathing leads to a lower respiratory rate and deeper breaths.

• These changes improve ventilatory efficiency without increasing lactate or perceived exertion — if you're adapted.

• In non-adapted individuals, VO₂max and performance may initially drop (~11% VO₂max reduction).

• Adapted athletes can reach similar VO₂max levels with nasal breathing as they can with mouth breathing.

There's nothing magical about this; essentially, if you are trained, it won't have a negative impact, but if you're not, it might. This also supports the idea that ventilation, or the amount of air your lungs can hold, isn't really the limiting factor. It's more about how much oxygen your lungs can transfer from the air into your blood (and ultimately into your cells).

Anaerobic Exercise and Airway Benefits

• Anaerobic power output (e.g. in a 30s Wingate test) is unaffected by breathing mode.

• Nasal breathing can significantly reduce bronchoconstriction in asthmatics.

Not surprisingly, 30 seconds is too brief a period to observe any benefits. However, for asthmatics, this might be worth trying!

Other Effects

• It increases nitric oxide (NO), which may improve oxygen delivery, though evidence is mixed.

• Nasal dilator devices can enhance airflow and delay the need to switch to oral breathing.

Nasal Breathing and Zone 2

Personally, I use it for z2. It's an excellent self-test: if you can sustain nasal breathing, you’re probably in Zone 2, where ventilation shouldn’t be a limiting factor. This encourages you to slow down, breathe more deeply, and remain aerobic. It also helps me breathe through my nose throughout the day and even at night. Nasal breathing enhances airflow and tongue positioning during sleep. This has been found to help reduce snoring — something I've also personally noticed.

Nervous System and Breathing Mechanics

• Slowing your breath increases HRV and stimulates the parasympathetic nervous system.

• Same amount of air with fewer, deeper breaths → calm and recovery.

• High-frequency shallow breaths → sympathetic activation (useful in short bursts).

  
  

Practical Recommendations

• Try Zone 2 training using only nasal breathing. If you start gasping, you’re above Z2.

• Use it during recovery work, walks, warm-ups, and cool-downs.

• Experiment with nasal breathing during sleep (even try taping if safe).

• If interested in high-intensity nasal work, commit to long-term adaptation — think 6+ months.

• Don’t expect magic. Use it as a tool to improve breathing efficiency, not as a performance hack.

  
  

Final Thought

Nasal breathing won’t turn you into an elite athlete — but it can sharpen your awareness, improve breathing mechanics, and support recovery. Like most things in training, it works best when you understand the context — and train it like any other skill.

Reference:Dallam, G., & Kies, B. (2020). The Effect of Nasal Breathing Versus Oral and Oronasal Breathing During Exercise: A Review. Journal of Sports Research, 7(1), 1–10.