A Reader Asks: "Why Do You Sometimes Breathe Through Your Mouth?"
A while ago, I received an email from a reader asking an excellent question:
Mouth breathing vs. nasal breathing — I noticed that Kushner Roshi, during demonstrations of Hara Breathing, often inhales through the mouth. My reading and practice suggest that nasal breathing is biologically superior for nervous system regulation and for health in general, both on the inhale and the exhale. Some authors even argue that habitual mouth breathing can be harmful (James Nestor's Breath is a convincing reference). Is there a technical reason why mouth breathing occurs so frequently in the demonstrations, or is it simply a personal habit?
The question caught me by surprise for two reasons.
First, it made me realize that I had never really addressed the issue of mouth breathing versus nose breathing—not in previous blog posts and not in the Hara Foundations course. That was an oversight on my part.
Second, I had never heard of James Nestor or his book Breath. I was surprised to discover that it was first published in 2020, has sold more than three million copies worldwide, and spent considerable time on the New York Times bestseller list. I thought I had kept up reasonably well with the breathing literature, but apparently not. I don't know how I missed it, and I'm grateful to the reader for bringing both the question and the book to my attention.
Why do I sometimes breathe through my mouth?
There are actually two reasons.
The first is that, in my Zen tradition, we have a number of breathing exercises in which we intentionally inhale through the mouth. These are generally strengthening exercises involving forceful breathing. They are training methods—not the way we ordinarily breathe during meditation or in daily life.
A useful analogy is weight training. We deliberately stress our muscles in order to make them stronger, but we don't walk around flexing them all day afterward. And, we might make grunting noises, hopefully only when we lift a heavy weight. In the same way, certain breathing exercises are designed to cultivate specific qualities, not to establish our everyday pattern of breathing. This reminds me of a lesson I learned from my Zen teacher.
In our tradition, we practice a form of breathing called “ah/um” breathing, named after the sounds made during inhalation and exhalation. The inhalation is forceful through the mouth, the exhalation through the nose, accompanied by exaggerated facial expressions—a wide-open mouth on the inhale and pursed lips on the exhale. I've included a short video below demonstrating "ah/um" breathing that we recorded for our upcoming course (more on that below).
One day, after practice, I sat down across from my teacher at lunch. Without thinking, I made audible "ah" and "um" sounds as I breathed, along with the accompanying facial gestures. He looked at me, shook his head, and asked, "What are you doing?"
"I'm setting my hara," I replied.
He smiled and said, "Don't go around doing that all the time. It makes you look eccentric."
I've never forgotten that lesson.
My own view is straightforward. For ordinary breathing, meditation, and daily life, I generally recommend nasal breathing. It aligns with traditional Zen practice and is supported by a growing body of physiological research. In that respect, modern physiology and traditional Zen point in much the same direction. The mouth has its place in certain training exercises and during strenuous exertion, but those are exceptions rather than the rule.
When we practice zazen, breathing is entirely different. In both inhalation and exhalation, we breathe quietly through the nose. Traditionally, the breath is said to be so gentle that a feather placed beneath the nostrils would not be disturbed.
The second reason I sometimes inhale through my mouth in the videos is purely practical. When I'm teaching, I often exaggerate the sounds of inhalation and exhalation so viewers can easily tell which phase of the breath I'm demonstrating. The audible "ah/um" sounds make it much easier for viewers to follow the demonstration.
Looking back, however, I can see how this could be misleading.
So let me state it plainly: Unless a particular exercise specifically instructs you to breathe through your mouth—or you're lifting a heavy weight—hara breathing, as practiced in Zen, is done through the nose, both on the inhalation and the exhalation.
The mouth-breathing you sometimes see in our demonstrations is simply a teaching device, not the recommended everyday practice.
So, as my teacher advised me many years ago, don't go around breathing through your mouth and looking eccentric.
About James Nestor's Book
I found Nestor’s book to be fascinating. I recommend it to anyone interested in the science of breathing. (He has a delightful term for people like us: "pulmonauts.") I'll have more to say about the book in my next post.
Looking ahead
Looking ahead, Ellen and I—together with our new collaborator, Alex Greene (who appears in the "ah/um" breathing video)—are currently recording a new Hara Foundations video course devoted to deepening and strengthening hara practice.
We still have quite a bit of editing ahead of us, so we don't yet have a release date. The video of Alex that I link to in this post comes from that series. We'll be sure to let you know as we get closer.