Mouth Wide Shut: A Self-Study Into the Science of Nose-Breathing


Study In Progress - This is a living article, with updates being added as regularly as they come. Check in regularly for updates. 

It has become almost comical in the way that many health trends have circulated around the electric avenues of social media to, most often, fizzle out without so much as a hiss or pop in the noisy world of self-improvement and well-being. 

And yet, more then ever, we've come to learn a rather dangerous lesson: health can be commercialized. And not only can it be commercialized, but it can also  tremendously profitable. 

Accordingly, we begin to see a formula take shape - somewhat of a pattern that begins to emerge amongst the static fuzz. A health claim, followed by the creation of a product, consecrated by a marketing campaign. In more expansive examples, we can begin to see the formation of an identity or icon who will then proceed to repeat steps one through three from variable angles. 

A lot of the time, rather surprisingly, we see that these individuals are not all that  qualified to be making such claims - they're simply reporters or authors who have tapped into a interested niche that is found to be ripe for exploiting. 

With this piece, I'll single out one and only one such example, though we encounter such individuals daily as they circuit podcasts and persistently feed information (and/or misinformation) through their social media channels. 

You may have heard of James Nestor. As per his own Q&A page, James states:  "I am a science journalist, and not a doctor nor therapist. [In bold] I cannot offer breathing advice for specific ailments."

Naturally, James published a book called Breath: The New Science of a Lost Art, in which he cultivates and presents the health evidence purporting to show that, very simply boiled down, breathing through the nose is exponentially more beneficial than breathing through the mouth. 

This self-study won't wade through the weeds and thickets of this particular debate. Personally, I myself have bought into this idea based on a medley of intuitive assumptions and my own research - which admittedly pales in comparison to James' own endeavor to understand (and, in turn, push) this claim.

In my continued attempts to validate questionable health claims with my own direct experience (something we should all probably be doing), I figured to put this health claim to the test as well - to see whether or not breathing through the nose is noticeably more beneficial than breathing through the mouth.


Unfortunately, measurement in the context of such a topic/question is tremendously difficult. In a sportive context, or in an athletic application (usually, a default forum to test hypotheses relating to health), there are far too many variables at play to effectively measure such subtle differences - without expensive measuring instrumentation or a team of scientists coordinating a painstakingly precise study. 

Cognitive ability itself remains too subjective and dynamic of an area to examine this kind of question; in other words, if cognitive ability was noticeably improved by breathing exclusively through the nose, we would all have all taped our mouths shut a long time ago. 

It then occurred to me, upon hearing James discuss the fact that he sleeps with his mouth taped shut in an effort to maximize breathing through his nose (we spend a third of our lives asleep, after all), that sleep may allow for a snug fit to test this hypothesis, offering the right blend of subjective and objective testing metrics. 

And so I went out to purchase my own micropore tape (available for $5 online to anyone interested) and, equipped with my impressively accurate sleep tracking device/app (which shall remain nameless for the sake of demonstrating that there is no sponsorship at play here), I sought to test this claim for myself. 

At first, it's a little daunting and the piece of tape remains hesitantly small as thoughts of suffocation swirl around the mind. Eventually, after a few nights sans death, the tape becomes bigger, as does the desire to satiate this particular curiosity. 

A few days in and I noticed no observable difference in my sleeping patterns. My ratio of deep sleep to light sleep to REM sleep remained largely the same, as did my deep sleep continuity and my overall duration of sleep to begin with.

Fittingly, the tracker I use accounts for breathing quality via the Sp02 reader, something that I'm not putting much weight into given the general inaccuracy of sp02 sensors in wrist-wearable fitness trackers.

In terms of the intangible measurements, my mood remained steady, my level of wakefulness and alertness didn't change all that much as I sought to keep external variables (namely nutrition, sleeping schedule and caffeine intake) as steady as I could.

But then things started to become more conclusive...


While I would usually go into a little bit of depth surrounding the science behind such claims, summarizing and contextualizing the various scientific studies that have been conducted to try and stitch some measure of purpose and intrigue into this article, life's too short. 

In light of this hakuna matata approach, I've decided to simply list a number of sources below for readers to springboard off of as they please. The research on this topic is, appropriately, abundant and divergent - there are multiple angles at which the instruments of science have approached this topic and countless conclusions that have been drawn, none of which necessarily clarify the day-to-day benefits that can be cultivated from nose-breathing. 

It's a context like this which makes the likes of James Nestor so appealing - as we have little time to study (let alone summarize studies) regarding such questions, we rely on investigative reporters to do it for us. While this is often a harmless and efficient method of cultivating knowledge, we must always be cautious about whether or not any other motives (book sales, reputations) are being pursued.,during%20exercise%20while%20breathing%20nasally.,103431



After the first few days, within which I had (admittedly) expected instantaneous results to no avail, I began comparing my sleep analytics, tape versus no tape.

I had only noted some very slight differences when comparing results day by day - amounting to a handful of more minutes spent in either deep sleep or REM sleep (amounting to a slightly improved overall sleep score). 

Nothing to write home about, but it was a start. In retrospect, this indication of increased REM/deep sleep, made possible with exclusive nose-breathing would go on to mean something quite considerable, no matter how insignificant the results initially seemed. 

Then, I had realized something: on nights where I had slept without tape, it may just have been that I had breathed mainly through my nose anyway, prompting me to sleep with my nose blocked to enforce only-mouth breathing. 

The results became a little more pronounced: 

Comparison A: 

Taped mouth: 
Total sleep: 7hrs 16 min
Deep sleep: 2hr 24 min
Light sleep: 2h 53 min
REM sleep: 1 hr 59 min

Taped nose:
Total sleep: 8hrs 3 min
Deep sleep: 2hr 34 min
Light sleep: 3h 47 min
REM sleep: 1h 42 min

The example above had proven to be emblematic of the larger pattern at play, one that would become all the more clear in the coming weeks. 

Astoundingly, despite having more overall sleep (8+ hrs with my nose taped shut), I had still been achieving lower levels of REM sleep and almost equivalent levels of deep sleep. 

In other words, even though I had more overall sleep, the quality of my sleep had been reduced while breathing exclusively through my mouth. 

As many times as I repeated this process, the results continued to validate the simple fact: sleeping while breathing solely though my nose resulted in better, deeper sleep. 

I still couldn't necessarily believe it. I figured that there had to have been other factors at play, as the differences couldn't be this obvious; if it were this simple, why would we not all be jumping aboard this trend? Why have we not discovered this sooner?

So I kept going, trying to account for other possible factors and trying to reinforce the validity. 

It hadn't been until one night whereby I had removed the tape roughly halfway through my sleep that I became immediately convinced:


I had removed the tape because of some allergies that had been acting up, resulting in a blocked nose that made it rather difficult to breathe. Upon removing the tape, I had slept the remainder of the night breathing through my mouth in, evidently, only a light sleep with a brief flash of deep sleep. 

To see the results this clearly had been a shock - one that prompted me to try this again and again. 

Update: 2020-09-23

Removed mouth tape midway through sleep, results showed a considerable decrease in deep sleep and a more consistent pattern of light sleep, while REM sleep remained the same. 


Coming soon: Further Repetition + Validation. 

Then.. Part II: Measuring the effects of nose-breathing in a sportive context. Initial results indicate a lower heart rate when exercising while breathing exclusively through the nose.