The Science

The Science

The Science of Nasal Breathing: What the Research Actually Shows

A breakdown of the peer-reviewed research on nasal breathing, airway resistance and athletic performance — including the Australian clinical trial behind nasal dilator strips.

Peer-reviewed Westmead Hospital, NSW Published 2019

§ Quick Answer

Nasal strips are external nasal dilators that mechanically widen the nasal valve — the narrowest point in your airway — to reduce nasal airway resistance. A 2019 clinical trial conducted at Westmead Hospital in Sydney (Wheatley et al., Advances in Therapy) found this reduced resistance and improved sleep in people with chronic nasal congestion. Less resistance means less energy wasted fighting to breathe — and more to spend on output.

§01 Mechanism

How Nasal Dilation Actually Works

Your nasal valve — the narrow passage just inside each nostril — is the single tightest point in your entire airway. Even a small amount of swelling, congestion, or structural narrowing here creates disproportionate airflow resistance, long before air reaches your lungs.

An external nasal strip uses a flexible band under tension to gently pull the sides of the nose outward, widening the nasal valve from the outside. This is a purely mechanical effect — no medication, no absorption into the body.

Nasal airway resistance ↓
39.1%
Reduction reported — Wheatley et al. (2019)
0%1020304050%

Measured reduction in nasal airway resistance with an external dilator strip in place.

2019
Year the pivotal nasal dilator strip study was published in Advances in Therapy
AU
Trial conducted at Westmead Hospital, New South Wales — not overseas

§02 Evidence

Peer-reviewed · 2019

The Study Behind the Claim

Wheatley JR, Amis TC, Lee SA, Ciesla R, Shanga G. — "Objective and Subjective Effects of a Prototype Nasal Dilator Strip on Sleep in Subjects with Chronic Nocturnal Nasal Congestion." Advances in Therapy, 2019.

Where it happened
Conducted in Australia, at Westmead Hospital, New South Wales — one of the only major nasal dilator studies run on home soil rather than overseas.
Who it studied
Adults with chronic nocturnal nasal congestion — people who regularly experience a blocked or restricted nose at night.
What it found
A meaningful reduction in nasal airway resistance, along with improvements in both objective and subjective measures of sleep quality.
What this means for you
If nasal congestion is limiting your airflow — whether that's at night or mid-session — mechanically widening the nasal valve is a well-evidenced way to address it.

Straight talk

This is the foundational research behind why external nasal dilation works at all. It's also the most commonly misquoted study in this category — plenty of nasal strip brands cite an oxygen or performance percentage that doesn't actually come from this trial.

We're not going to do that here.

§03 Performance

Nasal Breathing and Athletic Performance

Your nasal valve is the tightest point in your entire airway. Restrict it, and you're fighting your own body before you've even started the set, the sled push, or the final kilometre.

Nasal breathing filters, warms and humidifies every breath before it hits your lungs. It also triggers nitric oxide production — a natural vasodilator that widens blood vessels and supports oxygen delivery to working muscle.

Reducing nasal airway resistance means your body isn't wasting energy fighting to breathe. That's air you get to spend on output instead.

Why athletes reach for nasal dilation

  • 01Filters, warms and humidifies incoming air before it reaches the lungs.
  • 02Triggers nitric oxide production, supporting blood vessel dilation and oxygen delivery.
  • 03Removes a real, physical bottleneck when congestion, sweat, or nasal valve collapse restricts airflow — exactly the conditions HYROX, CrossFit and endurance training create.

§04 Comparison

Nasal Strips vs Mouth Tape

These address two different points in the same system.

Nasal strips

Widen the nasal valve from the outside

Reducing resistance to airflow through the nose — a mechanical change at the tightest point in the airway.

Mouth tape

Keep the lips gently closed

Encouraging nasal breathing instead of mouth breathing — particularly useful overnight, when mouth breathing is easiest to fall into unnoticed.

A supporting trial on mouth taping (Lee et al., PMC9498537) found associations between nasal breathing during sleep and reduced markers of disrupted breathing, reinforcing why the two products are often used as a pair rather than a substitute for one another.

§ FAQ

Common Questions

Q1Do nasal strips actually work?
They mechanically widen the nasal valve, the narrowest point in your nasal airway. The 2019 Wheatley et al. trial found this meaningfully reduced nasal airway resistance and improved sleep quality in people with chronic nasal congestion.
Q2How does nasal breathing help performance?
By reducing resistance at the nasal valve, nasal breathing lets more air move with less effort, while triggering nitric oxide production that supports oxygen delivery to working muscle. Less energy wasted on restricted breathing means more available for output.
Q3What's the difference between nasal strips and mouth tape?
Nasal strips widen the nose from the outside to reduce airflow resistance. Mouth tape keeps the lips gently closed to encourage nasal breathing instead of mouth breathing. They target different points in the same breathing pattern and are commonly used together.
Q4Was this research conducted in Australia?
Yes. The pivotal Wheatley et al. (2019) nasal dilator strip trial was conducted at Westmead Hospital in New South Wales.
Q5Do nasal strips reduce snoring?
Nasal strips can reduce snoring caused by nasal congestion or a narrow nasal valve. Snoring caused by other factors, such as soft palate collapse or sleep apnea, is a different mechanism and should be assessed by a medical professional.

References

  • Wheatley JR, Amis TC, Lee SA, Ciesla R, Shanga G. "Objective and Subjective Effects of a Prototype Nasal Dilator Strip on Sleep in Subjects with Chronic Nocturnal Nasal Congestion." Advances in Therapy. 2019 Jul;36(7):1657–1671. PMC6822853
  • Lee SA, et al. Mouth taping and nasal breathing during sleep. PMC9498537
  • Nestor, J. and Stanford University research on nitric oxide and nasal breathing — referenced for background context.
  • ClinicalTrials.gov record, Wheatley et al. trial, Westmead Hospital, NSW. NCT03105297

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This page is for general information only and does not constitute medical advice. Individual results and experience may vary. XLR8+ Labs products are not intended to diagnose, treat, cure or prevent any medical condition. If you have concerns about sleep apnea or another medical condition, consult your GP.