Nasal Breathing
Breathing through your nose instead of mouth for nitric oxide production, better oxygen delivery, and improved sleep
Bottom Line
Nasal breathing is one of the most underrated health interventions. Your nose isn't just an air filter - it's a nitric oxide factory. Breathing through your nose produces 15-20% of your body's nitric oxide, a molecule that dilates blood vessels, kills pathogens, and improves oxygen delivery to tissues.
The research is clear: mouth breathing is associated with sleep apnea, dental problems, facial development issues in children, and reduced exercise performance. Nasal breathing improves all of these while costing nothing.
If you're breathing through your mouth during the day or sleeping with your mouth open, fixing this is one of the highest-ROI changes you can make. Pairs perfectly with mouth taping for sleep.
Science
Nitric Oxide Production:
The paranasal sinuses continuously produce nitric oxide (NO). When you breathe through your nose, this NO is carried into the lungs where it: - Dilates blood vessels (vasodilation) - Improves oxygen uptake in alveoli - Kills bacteria, viruses, and fungi - Regulates blood pressure
Mouth breathing bypasses this entirely - you get zero nasal NO.
The Bohr Effect & Oxygen Delivery:
Nasal breathing naturally slows respiration and increases CO2 tolerance. Higher CO2 levels shift the oxygen-hemoglobin dissociation curve rightward (Bohr effect), meaning hemoglobin releases MORE oxygen to tissues.
Paradoxically, breathing less (through your nose) delivers more oxygen than breathing more (through your mouth).
Key Research:
- Lundberg et al. (1995): Discovered high NO concentrations in nasal airways
- Recinto et al. (2017): Nasal breathing during exercise reduced ventilation rate by 22% with equal performance
- Multiple studies link mouth breathing to sleep disordered breathing, dental malocclusion, and reduced quality of life
Mechanisms Summary:
- Nitric oxide delivery - Antimicrobial, vasodilating, bronchodilating
- Air conditioning - Filters particles, humidifies to 95-100%, warms to body temperature
- CO2 retention - Improves oxygen delivery via Bohr effect
- Parasympathetic activation - Nasal airflow stimulates calming nervous system response
- Reduced over-breathing - Prevents chronic hyperventilation
Effect Sizes:
- Nitric oxide: 6x higher concentration in nasal vs. oral breathing
- Exercise efficiency: ~10-20% reduction in ventilation at same workload
- Sleep quality: Significant improvement when mouth breathing corrected
Supporting Studies
12 peer-reviewed studies
View all studies & compare research →Practical Protocol
Daytime Protocol:
- Awareness first: Notice when you're mouth breathing (stress, concentration, exercise)
- Lips together, tongue on roof: Rest position should be mouth closed, tongue lightly touching palate
- Breathe through nose: All day, every day, as default
- During exercise: Start with low intensity nasal-only, gradually increase threshold
Sleep Protocol:
- Use mouth taping to ensure nasal breathing during sleep
- Address nasal congestion first (see below)
- Consider nasal dilator strips if needed
Exercise Progression:
| Week | Protocol |
|---|---|
| 1-2 | Nasal breathing during warm-up and cool-down only |
| 3-4 | Nasal breathing during Zone 1-2 cardio |
| 5-6 | Nasal breathing up to ventilatory threshold |
| 7+ | Nasal breathing as long as possible, mouth as needed |
Nasal Congestion Solutions:
- Acute: Nasal rinse (neti pot), steam inhalation, Breathe Right strips
- Chronic: Address allergies, consider turbinate evaluation, check for deviated septum
- Exercise-induced: 5-10 minutes of light nasal breathing usually opens passages
The "Nose Unblocking" Exercise:
- Take a small breath in through nose
- Small breath out through nose
- Pinch nose and hold breath
- Walk around until moderate air hunger
- Release and breathe gently through nose
- Wait 30-60 seconds, repeat if needed
Common Mistakes:
- Forcing nasal breathing during high-intensity exercise (allow mouth breathing at VO2max efforts)
- Not addressing underlying congestion issues
- Expecting instant adaptation (takes 2-6 weeks)
Risks & Side Effects
Known Risks:
- Essentially none for healthy individuals
- May feel uncomfortable initially if deconditioned to nasal breathing
Contraindications:
- Severe nasal obstruction (deviated septum, polyps) - address first
- Acute sinus infection - wait until resolved
- During very high intensity exercise where oxygen demand exceeds nasal capacity
Cautions:
- If you cannot breathe through your nose at rest, see an ENT
- Persistent one-sided blockage warrants medical evaluation
- Don't force it during intense exercise - allow mouth breathing when needed
Interactions:
- Enhances effects of all other breathwork practices
- Synergistic with mouth taping
- Improves CO2 tolerance training
Who It's For
Ideal for:
- Chronic mouth breathers (during day or sleep)
- People with poor sleep quality
- Endurance athletes seeking efficiency
- Anyone with frequent respiratory infections
- People who wake with dry mouth
- Those with mild anxiety (nasal breathing is calming)
Signs you need this:
- Dry mouth upon waking
- Snoring or sleep apnea symptoms
- Frequent throat clearing
- Getting winded easily during light activity
- Visible mouth breathing habit
May need modifications:
- Those with structural nasal issues (get evaluated first)
- Elite athletes at VO2max efforts (mouth breathing is fine here)
- People with severe allergies (address allergies simultaneously)
How to Track Results
What to Measure:
- BOLT score (Body Oxygen Level Test): Time from end of normal exhale to first urge to breathe
- <10 seconds: Poor (likely chronic over-breather)
- 10-20 seconds: Fair
- 20-40 seconds: Good
- 40+ seconds: Excellent
- Morning mouth dryness (1-10 scale)
- Snoring (use app like SnoreLab)
- Exercise nasal breathing duration before needing mouth
How to Test BOLT Score:
- Rest for 5 minutes
- Take a normal breath in through nose
- Normal breath out through nose
- Pinch nose and start timer
- Stop at FIRST urge to breathe (not maximum hold)
- Record time
Tools:
- SnoreLab app - Free snoring tracker
- BOLT score tracking - Manual or app
- Pulse oximeter - Verify oxygen saturation
- Nasal dilator strips - For sleep if needed
Timeline:
- Daytime habit: 1-2 weeks to establish awareness
- Exercise adaptation: 4-8 weeks to increase threshold
- BOLT score improvement: 2-4 weeks with consistent practice
- Sleep quality improvement: 1-2 weeks (with mouth taping)
Signs It's Working:
- Waking with moist mouth (not dry)
- Reduced or eliminated snoring
- Improved exercise tolerance at nasal-only breathing
- Higher BOLT score
- Calmer baseline state
- Fewer respiratory infections
Top Products
Nasal Dilators:
- Breathe Right Strips - External adhesive strips, most popular
- Intake Breathing - Magnetic strips, reusable
- Mute Nasal Dilator - Internal silicone dilator
- Turbine - Internal dilator for athletes
Nasal Rinse:
- NeilMed Sinus Rinse - Squeeze bottle, easy to use
- Navage - Powered nasal irrigation
- Traditional Neti Pot - Gravity-fed, classic
Mouth Tape (for sleep):
- See mouth taping for full recommendations
- Hostage Tape - Popular, comfortable
- 3M Micropore tape - Budget option, medical grade
What to Avoid:
- Nasal decongestant sprays for more than 3 days (rebound congestion)
- Anything claiming to permanently "fix" breathing with a device
Cost Breakdown
Free - completely.
Nasal breathing costs nothing. You already have a nose.
Optional Accessories:
- Mouth tape: $5-15 for months of supply
- Nasal dilator strips: $10-15 per box
- Neti pot: $10-20 one-time
- Saline spray: $5-10
If Nasal Obstruction Exists:
- ENT evaluation: $100-300 (with insurance)
- Allergy testing: $200-1,000
- Turbinate reduction (if needed): $2,000-5,000
- Septoplasty (if needed): $5,000-10,000
Cost-Benefit:
For most people, this is completely free and provides substantial benefits. Only pursue medical intervention if you cannot breathe through your nose at rest despite trying the basic protocols.
Recommended Reading
Podcasts
How to Breathe Correctly for Optimal Health, Mood, Learning & Performance
The physiological sigh (double inhale, long exhale) is the fastest way to calm down. Nasal...
Dr. Jack Feldman: Breathing for Mental & Physical Health & Performance
Mouth breathing causes structural and health problems; nasal breathing filters air and produces...
Fitness Toolkit: Protocol & Tools to Optimize Physical Health
Build your weekly fitness around 150-200 minutes of zone 2 cardio (conversational pace, nasal...
Essentials: Breathing for Mental & Physical Health & Performance | Dr. Jack Feldman
Slow, controlled breathing directly reduces anxiety by activating specific neural pathways -...
Discussed in Podcasts
54 curated moments from top health podcasts. Click any timestamp to play.
How nasal breathing affects facial development and attractiveness
McKeown explains the connection between nasal breathing, facial structure, and attractiveness, noting that forward jaw growth indicates good airway development.
"It's the high cheekbones, it's the forward growth of the jaws, it's the maxilla that's forward, it's the mandible that's forward, it's the teeth that are straight. But more importantly, when the face grows that way, what's the airway?"
McGill curl-up: tongue on roof of mouth, breathe through nose while strengthening abs
The curl-up replaces sit-ups for back pain. Tongue on roof of mouth with nasal breathing during the exercise supports proper head and neck position.
"Your tongue is on the roof of your mouth. Tongue on the roof of the mouth often puts the head in a neutral position, which is important for spine health."
Neck strengthening with nasal breathing improves airway passage and spine stability
Static chin-tuck contractions with tongue on roof of mouth and nose breathing strengthen front neck muscles, improving airway and spine health.
"I'm a big proponent of nasal breathing, unless you need to breathe through your mouth, both during sleep and sometimes during exercise, but certainly at rest."
Dr. Feldman: the pre-Botzinger complex fires every breath and drives diaphragm activation
Every breath starts with neurons in the pre-Botzinger complex firing, which then activates the diaphragm and intercostals. Nose vs.
"I don't think we fully have the answer to that. Clearly, there are differences between nasal and mouth breathing."
Nasal breathing improves memory via hippocampal activation during inspiration
Studies in the Journal of Neuroscience show that restricting breathing to the nose activates the hippocampus during inspiration, improving memory.
"One looking at olfactory memory. So that kind of made sense because you can smell things better through your nose than your mouth, unless you're some sort of elk or something where they can, presumably they have some sense of smell in their mouth as well. But humans generally smell with their nose. That wasn't terribly surprising, but there was a companion study that showed that the hippocampus, terribly surprising, but there was a companion study that showed that the hippocampus, an area involved in encoding memories in one form or another, was more active, if you will, and memory and recall was better when people learned information while nasal breathing as opposed to mouth breathing. Does that make sense from any mechanistic perspective?"
Quality sleep is the top defense against colds and flu
Getting enough sleep to avoid daytime sleepiness is the foundational protocol for maintaining immune function against illness.
"However much you need in order to not feel sleepy during the day, except maybe the requirement for a short nap of 10 to 30 minutes."
Switching from mouth to nose breathing — blood pressure, sleep, and cognition all improved in days
James Nestor describes an experiment where subjects were forced to mouth-breathe, and within days blood pressure climbed, sleep became fragmented, cognitive function dropped, and stress hormones surged. Their physiology began to resemble people decades older, mirroring how many people unknowingly breathe every night.
"The changes were dramatic, blood pressure climbed, sleep became fragmented, cognitive function dropped, stress hormones surged. Within days, their physiology began to resemble that of people decades older."
Nasal breathing vs mouth breathing — the single biggest factor for snoring and sleep apnea
Nestor explains that nasal breathing versus mouth breathing is one of the three key factors determining whether someone suffers from snoring and sleep apnea. Mouth breathers are significantly more likely to develop these conditions, which have cascading effects on health.
"So the third thing is nasal breathing versus mouth breathing. And if you are a mouth breather, you are going to be much more apt to suffer from snoring."
Breastfeeding trains obligate nasal breathing — modern soft foods broke this pattern
Nestor explains that breastfeeding naturally trains infants to be obligate nasal breathers because feeding through the breast while breathing is only possible through the nose. The historical shift from hard foods to processed soft foods and bottles disrupted this natural development of nasal breathing patterns.
"to be obligate nasal breeders because they're breastfeeding for three, four hours a day, right? The only way you can feed and breathe is through your nose."
Nasal breathing protects your microbiome: distinct microbial communities from nose to gut
Different body regions (eyes, mouth, nose, gut) host distinct microbiomes.
"It's well established that there are healthy microbiota that live all along that length and they differ along that length."
Elongated exhale through nose activates parasympathetic calm
Immunologist Jenna Machoki explains how elongating the exhale through the nose taps into the parasympathetic nervous system to reduce stress. The diaphragm movement affects heart rate via the respiratory sinus arrhythmia, helping balance the autonomic nervous system.
"And elongating the exhale, so just taking a normal inhale and then making sure that exhale is slowed down through the nose. This is going to really tap into that rest and digest parasympathetic part of the nervous system."
Tongue placement and nasal breathing to exit fight-or-flight
Dr. Nickelston introduces a daily exercise combining tongue placement at the roof of the mouth with nasal breathing and cervical extension to help shift the nervous system out of chronic fight-or-flight patterns.
"tongue placement at the roof of the mouth, which will be really great. Also working a muscle in your neck called your platisma."
Who to Follow
Researchers & Experts:
- Patrick McKeown - Author of "The Oxygen Advantage," leading breathing educator, developed BOLT score
- James Nestor - Author of "Breath," investigative journalist who popularized nasal breathing research
- Andrew Huberman, PhD - Covers nasal breathing mechanisms extensively
Historical:
- George Catlin (1796-1872) - Artist who wrote "Shut Your Mouth and Save Your Life" after observing Native American breathing habits
Practitioners:
- Brian Mackenzie - Endurance coach, teaches nasal breathing for performance
- Wim Hof - While known for hyperventilation techniques, emphasizes nasal breathing for baseline
Synergies & Conflicts
Pairs Perfectly With:
- Mouth Taping - Enforces nasal breathing during sleep
- CO2 Tolerance Training - Both improve CO2 tolerance
- Cyclic Sighing - Use nasal inhale for maximum benefit
- Zone 2 Cardio - Ideal intensity for nasal-only training
- HRV Training - Nasal breathing improves HRV
Stacks:
- Sleep Stack: Nasal breathing + mouth taping + cool room
- Endurance Stack: Nasal breathing + Zone 2 + CO2 tolerance training
- Calm Stack: Nasal breathing + cyclic sighing + morning sunlight
Performance Progression:
- Master daytime nasal breathing (Week 1-2)
- Add mouth taping for sleep (Week 2-3)
- Introduce nasal breathing during light exercise (Week 3-6)
- Progressively increase exercise intensity with nasal breathing (Week 6+)
What It Enhances:
- All cardio becomes more efficient
- Sleep quality improves
- Stress resilience increases
- Other breathwork practices become more effective
What People Say
Why It's Gaining Attention:
Common Positive Reports:
Common Challenges:
Reddit Communities: