“The greatest indicator of life span wasn’t genetics, diet, or the amount of daily exercise, as many had suspected. It was lung capacity.”
When was the last time you thought about your breathing? Like, REALLY thought about it? Not just “inhale, exhale, stay alive” — but the actual mechanics of how air enters your body and what it does once it gets there?
If you’re like me, the answer is probably never. Breathing was always just… automatic. Background noise. Something your body handles while you’re busy thinking about everything else.
Then James Nestor comes along and says, “Hey, you’ve been doing it wrong your entire life.” And honestly? After reading Breath, I think he might be at least partially right.
The Pseudoscience Question
This book makes you wonder how much fluffy pseudoscience is included. We delve into a handful of potentially exaggerated claims of simply fixing your breathing to solve the plethora of health problems highlighted in the introduction of this book. But how much can breathing really solve, especially when related to pervasive health problems that are usually associated with dietary or environmental issues? How much can an asthmatic fix their asthma if they are consuming inflammatory foods such as meat and dairy, or living in a heavily vehicle-congested city?
These are fair questions. And to Nestor’s credit, he does eventually address them — but you have to get through a lot of bold claims first.
The CO2 Contradiction
In one chapter we learn that breathing too much can be a problem, because we end up with less carbon dioxide in our system, and scientifically it has been proven to be beneficial to have more CO2. But then a chapter or two later, we learn about the Tummo or Wim Hof methods, which basically involve hyperventilating and loading ourselves up with oxygen to achieve a desired state in the body.
So which is it? Breathe less or breathe MORE? This contradiction bugged me while reading, and Nestor doesn’t fully reconcile it. The answer seems to be that different techniques serve different purposes — slow breathing for everyday calm, aggressive breathing for short bursts of physiological control. But the book could have done a better job connecting those dots.
That said, the Wim Hof sections are genuinely fascinating. The guy sits in ice baths and climbs mountains in shorts. His body basically learned to generate heat on command through breathing alone. Whether you believe all the claims or not, the documented results are hard to ignore.
The Nose Breathers
Then we learn about a certain group of Native Americans in the USA who were taller and more muscularly built than other populations, because of their diehard focus on only breathing through their nose. This was one of the most interesting parts of the book for me.
Nestor presents old photographs and dental records showing that indigenous populations who breathed through their noses had wider jaws, straighter teeth, and fewer respiratory problems. Then he compares them to modern humans — mouth breathers, essentially — and the difference is STARK. Crooked teeth, narrow airways, sleep apnea, snoring. All connected to how we breathe.
The implication? Modern humans literally changed the shape of their faces by switching from nose breathing to mouth breathing. Our processed diets softened our food, our jaws shrank, our airways narrowed, and now we can’t breathe properly. It’s a compelling argument, and it’s backed by actual anthropological evidence.
The Mystical Stuff
Then the author dives into the ancient breathing gurus who used mystical words to describe energy in the body, and you start to think this is going into metaphysical gibberish. Although the author does try to reduce it to some actual science, he doesn’t discount the pseudo-energy magic.
Look, I’m all for ancient wisdom. But when someone starts talking about “prana” and “chi” as literal forces flowing through your body, my skeptic alarm goes off. Nestor walks a fine line here — he’s clearly fascinated by these traditions, but he also tries to anchor them in measurable physiological effects. Sometimes it works. Sometimes it feels like a stretch.
I think the strongest parts of the book are where Nestor sticks to hard science — lung capacity studies, CO2 tolerance research, the Stanford nasal breathing experiment he personally participated in. When he ventures into the spiritual territory, the book loses some credibility. Not all of it, but enough to notice.
What Actually Changed for Me
In the last chapter, he summarizes every breathing technique presented in the book, and finally places a disclaimer that obviously you can’t fix everything with just breathing. Nonetheless, because of this book, I now actively force myself to do more nasal breathing when going to sleep or practicing sports — but only after a few YouTube videos from medical professionals who highlighted the benefits.
And here’s the thing — it actually works. Taping my mouth shut at night sounded INSANE when I first read about it. But after trying it for a week, I noticed I was waking up less, sleeping deeper, and not feeling like a dried-out husk in the morning. Is it the cure for everything? No. But for something that costs literally nothing and takes zero effort, the improvement was noticeable.
I also started paying attention to how I breathe during workouts. Turns out, I was a classic mouth breather — gulping air like a fish out of water. Switching to nasal breathing during lighter exercises forced me to slow down, control my heart rate, and actually USE my diaphragm. It felt unnatural at first, but now it’s second nature.
Final Thoughts
I give this book a 4/5 because it opens up a new frontier of science that needs further validation, but could potentially be revolutionary in the ongoing discoveries of enhancing human health and longevity.
Nestor is a journalist, not a doctor, and it shows in places. He’s drawn to dramatic stories and ancient mysteries more than clinical precision. But that’s also what makes the book readable — this isn’t a dry medical textbook. It’s an adventure through the lost science of breathing, and it’s genuinely entertaining.
If you’re someone who snores, has trouble sleeping, or just wants to understand why something as basic as BREATHING deserves your attention — pick this one up. Just keep your critical thinking cap on while you read it.
Thanks for reading.
— Leonidas
