Breath: The New Science of a Lost Art
Shows how the way you breathe, through the nose or mouth, fast or slow, shapes your blood pressure, sleep, face and mood, and how a few simple habits can restore a skill most people have lost.

Table of Content
1. Introduction
52 sec
Most of us breathe the way we blink, without a thought, and that habit may be costing us sleep, calm and even the shape of our faces. In Breath, journalist James Nestor notes estimates that around half of people breathe mostly through the mouth, and he shows what that does by plugging his own nose for ten days. His argument is that the way you breathe, through which opening, how fast and how fully, reshapes both body and mind, and that modern life has made most of us poor at it.
The reporting ranges from a choir director who got emphysema patients walking again to a yogi who drove his heart to 300 beats a minute and a dentist whose rejected ideas later became mainstream. What it leaves you with is a set of habits small enough to start today, beginning with a breathing pace that prayer traditions across the world already share.
2. Let your nose do the breathing it was built for
1 min 41 sec
A journalist spent ten days unable to breathe through his nose, and his body reacted in ways he did not expect. Monkeys put through a similar test changed even more, and then changed back.
3. Soft food shrank our mouths, and chewing can help
1 min 58 sec
Bigger brains and the gift of speech came with hidden costs for the human airway. Yet the steepest decline is surprisingly recent, and a nineteenth-century traveler believed he had found the cure.
4. Empty your lungs fully to breathe in more
1 min 41 sec
Emphysema patients at a New Jersey hospital were gasping for air, and doctors assumed little could be done. A choir director with no medical training saw a problem everyone else had missed.
5. Slow each breath to five and a half seconds
1 min 36 sec
Rosaries, mantras and chants from opposite ends of the world share an odd detail of timing. The reason it helps lies in a gas most people think of as useless.
6. Grow a wider airway with tongue posture and chewing
1 min 45 sec
A dentist lost his license for warning that standard treatments were making mouths smaller. His simplest fix costs nothing, and a chewing device helped one adult grow new bone in his face.
7. See how far breath control can push the body
1 min 55 sec
A yogi in Kansas made his heart race at a rate that should have killed him. Monks melt snow with body heat. The method behind both runs against everything gentle breathing teaches.
8. Carbon dioxide can bring both panic and lasting calm
1 min 55 sec
One psychologist found a legal route to LSD-like visions using nothing but breath. A neurologist works in the opposite direction, setting off panic on purpose, and finds something unexpected on the other side.
9. Conclusion
1 min 10 sec
Nestor’s reporting adds up to an odd picture. One of the most basic things a body does has been a side topic for Western medicine, and many of its pioneers, a choir director and a dentist who lost his license among them, worked outside the mainstream. Elsewhere, the knowledge is ancient. About 3,000 years ago, thinkers in India described prana and those in China described ch’i, a life force concentrated in living things and best drawn in through the breath. The earliest yoga texts, the Yoga Sutras, dating to about 500 BCE, say little about movement. They are mostly about sitting still and building that energy by breathing.
You do not need to believe in prana to use any of it. Close your lips and rest the tongue against the upper palate, so the nose is able to filter and warm the air. When pressure builds, let the exhale finish before the next breath begins. And for five or ten minutes a day, breathe in for five and a half seconds and out for five and a half.
George Catlin’s advice from the 1830s still holds, and it fits in three words: shut your mouth.
About this book
What is this book about?
Breathing feels automatic, so most people never think about how they do it. James Nestor argues that this is a mistake. By some estimates, around half of us breathe mostly through the mouth. That habit, made worse by three centuries of soft, processed food, can raise blood pressure, disturb sleep, crowd the teeth and narrow the airway. Nestor investigates by experimenting on himself, from ten days with plugged nostrils to a dose of concentrated carbon dioxide. He also seeks out people who relearned breathing away from conventional medicine: a choir director who got emphysema patients using their lungs again, a dentist stripped of his license for ideas that later gained acceptance, a yogi able to speed up and slow down his heartbeat on command, and a former Dutch mail carrier who completed a half-marathon within the Arctic Circle with his chest bare. Readers learn why the nose matters, why carbon dioxide is far more than waste, and how full exhales and chewing can expand lungs and airways. They also learn why a breath of about five and a half seconds in and out sits at the heart of prayer traditions around the world, and how to practice it for a few minutes a day.
Book Information
Who it's for
Wired, tired desk workers
Desk workers who feel wired and tired and want a calming tool that takes minutes a day.
Snoring or sleeping badly
People who snore, sleep badly or catch themselves breathing through the mouth.
Yogis and meditators
Yoga and meditation fans curious about the science behind slow breathing and methods like Wim Hof's.
About the Author
James Nestor
James Nestor is an American journalist and author, born in Tustin, California, who has written for The New York Times, The Atlantic, Scientific American and Outside. Breath, published in 2020, stayed on the New York Times bestseller list for 18 weeks during its first year and was named the best general nonfiction book of 2020 by the American Society of Journalists and Authors. His earlier book, Deep, published in 2014, explored freediving and what the ocean tells us about ourselves.
Ratings & Reviews
Ratings at a glance
What people think
Listeners find this work to be a superb listen that is extensively researched and packed with deep insights. They value how it highlights the necessity of correct breathing methods, with a specific emphasis on nasal breathing, and how these techniques enhance general wellness and help manage chronic ailments. Listeners admire the narrative style, with one observer noting it is written without ego, and they appreciate the actionable exercises and advice offered throughout the chapters.
Top reviews
Ever wonder why humans are the only species with crooked teeth? Nestor takes us on a wild ride through history to explain how our transition to soft, processed foods essentially shrivelled our mouths and ruined our airways. This isn't just a book about breathing; it’s an investigation into human devolution. The writing is incredibly accessible, blending humor with some pretty shocking experiments, like the author literally plugging his nose for ten days to prove how damaging mouth-breathing is. I found myself consciously closing my mouth and adjusting my posture while reading. It’s rare to find a science book that is this gripping and immediately applicable to your daily life. The sections on how nasal breathing can regulate heart rate and blood pressure were particularly eye-opening for me. A total must-read for anyone interested in longevity and holistic health.
Show moreAs someone who has struggled with chronic sinus infections for years, this book felt like a manual for my own body that I never knew existed. James Nestor has a gift for making complex biological processes feel like a thrilling detective story. I was fascinated by the 'pulmanauts' he interviewed—those fringe scientists and explorers who have spent decades uncovering lost breathing techniques from ancient cultures. The practical advice on the 5.5-second inhale/exhale rhythm has already helped me manage my daily stress levels. Honestly, the realization that we can actually expand our lung capacity and reshape our jaws through proper technique is life-changing. I’ve started using a tiny piece of tape on my lips at night, and I wake up feeling more refreshed than I have in a decade. It’s brilliant, well-researched, and written with a genuine sense of curiosity.
Show moreNestor writes with a refreshing lack of ego, which is rare in the biohacking space. Instead of acting like an all-knowing guru, he positions himself as a journalist on a quest for the truth, which makes the information much easier to digest. The book highlights how modern medicine often ignores the root causes of respiratory issues in favor of quick-fix medications. I was particularly moved by the stories of people who used simple breathing techniques to help manage autoimmune diseases and asthma. It’s a powerful reminder that the most basic biological function we perform—something we do 25,000 times a day—is often the one we understand the least. The bibliography is massive, which satisfied my need for academic proof. It is easily one of the most important health books published in the last decade. Everyone with a nose should read this.
Show moreLook, I was skeptical about the idea of taping my mouth shut at night, but the results speak for themselves. Before this book, I just assumed my snoring and dry mouth were unavoidable parts of aging. Nestor’s deep dive into the 'lost art' of nasal breathing completely flipped my perspective on its head. The way he explains the chemistry of carbon dioxide—how it’s not just a waste product but a crucial component for oxygen delivery—was a lightbulb moment for me. The book moves quickly from 19th-century catacombs to high-tech sleep labs in San Francisco. It’s incredibly well-paced. My only tiny gripe is that I wanted even more on the specific exercises, but the narrative flow is so good that I can see why he kept it focused on the journey. I've already bought three copies for my family members who struggle with sleep apnea.
Show moreThe truth is, we have become a species of 'mouth breathers,' and the health implications are far more terrifying than I realized. This book is a wake-up call. I was captivated by the history of how our skulls have changed since the industrial revolution. Nestor makes a compelling case that our narrow faces and crowded teeth are a direct result of our poor breathing habits and soft diets. I loved the blend of travelogue and science; one minute you’re in an ancient burial site, and the next you’re learning about the biochemistry of blood pH. It’s dense with information but never feels dry or academic. I’ve started practicing the 'Tummo' style breathing mentioned in the later chapters, and the boost in my energy levels is palpable. This is one of those rare books that changes how you move through the world.
Show morePicked this up on a whim, and it has completely changed how I approach my daily exercise routine. As a runner, I always thought huffing and puffing through my mouth was just how it worked when you pushed yourself. Nestor explains why that’s actually counterproductive and how nasal breathing can improve CO2 tolerance and endurance. The book is filled with these little counter-intuitive nuggets of wisdom. I especially appreciated the sections on how dentists are starting to recognize the link between jaw structure and respiratory health. It’s a very holistic look at the human body. James Nestor has a way of taking a subject that sounds incredibly boring—breathing—and turning it into a page-turner. I finished it in two sittings. If you care about your physical performance or just want to stop feeling tired all the time, buy this book.
Show moreWhat if the secret to health isn't a new pill or a complicated diet, but something we’re already doing every second? This book is a masterclass in science journalism. Nestor takes a deep dive into the 'Great De-evolution' of the human face and how our modern environment has made us the worst breathers in the animal kingdom. The stories of people reversing chronic conditions simply by changing their breath are nothing short of miraculous, yet they are backed by significant research. I loved the 'Breathwork' appendix at the back which summarizes the different techniques. It makes the book feel like a permanent reference guide rather than a one-time read. It's humorous, slightly gross at times (the nose-plugging experiment!), and ultimately very hopeful. It’s the kind of book you want to talk about with everyone you meet. Essential reading for the modern age.
Show moreThe chapter on the Stanford experiment was genuinely hard to get through because it made me feel so claustrophobic just imagining it. Nestor really went the extra mile by becoming a human guinea pig for his research, which adds a layer of authenticity you don't usually see in health books. I did find some of the claims regarding the 'superpowers' of ancient breathers to be a little bit on the fringe side, but the core science regarding CO2 levels and oxygenation is solid. It’s a fast-paced read that manages to be both informative and entertaining. I would have liked a few more diagrams of the exercises, but the resources on his website make up for it. If you’re a mouth-breather or a snorer, you really can’t afford to skip this. It’s a solid four stars for the sheer amount of 'aha!' moments I had.
Show moreAfter hearing about this book on several podcasts, I finally dove in, and I’m glad I did. The historical perspective on George Catlin and his observations of Native American breathing habits was fascinating. Nestor does a great job of showing how we’ve ignored ancient wisdom in favor of modern convenience. My only critique is that the book can feel a bit repetitive in the middle sections as he reinforces the 'nose good, mouth bad' mantra. However, the science is so vital that I didn't mind the reinforcement too much. The writing style is punchy and smart. I’ve already noticed a difference in my running performance just by switching to nasal breathing during my morning jogs. It was uncomfortable at first, but now I feel like I have a second wind that I never had before. Definitely worth your time.
Show moreWhile the research into the 'pulmanauts' is undeniably deep, I found some of the evolutionary claims regarding our ancestors' faces a bit too speculative for my liking. The author spends a lot of time on anecdotal success stories which, while inspiring, occasionally felt like they were drifting into the realm of pseudoscience. For instance, some of the theories about 'chewing ourselves' into better health felt a bit oversimplified. That said, the actual breathing techniques described—like the Box Breathing used by Navy SEALs—are very practical and have helped me stay calm during stressful work meetings. It’s an interesting read for sure, and Nestor is a talented storyteller, but I’d recommend keeping a healthy sense of skepticism while moving through the more 'miraculous' chapters. It’s a decent book, just take some of the broader claims with a grain of salt.
Show moreQuestions about this book
What is the main idea of Breath by James Nestor?
Nestor argues that how we breathe shapes our health far more than we assume. Breathing through the mouth, a habit he says around half of people share, can raise blood pressure and harm sleep, while slow, light breathing through the nose improves blood flow. He traces our poor breathing to evolution and to three centuries of soft food, and shows that habits like nasal breathing, full exhales and more chewing can reverse much of the damage.
Why is nose breathing better than mouth breathing?
The nose filters, warms and moistens the air, and breathing through it releases chemicals that help lower blood pressure and regulate the heart rate. When Nestor breathed only through his mouth for ten days, his blood pressure rose by an average of 13 points, his sleep suffered and his nose developed an infection. Monkeys forced to mouth breathe in Egil P. Harvold’s experiments developed narrower dental arches and crooked teeth.
What breathing technique does James Nestor recommend?
His simplest recommendation is to breathe in for about five and a half seconds and out for about five and a half seconds, which comes to roughly five and a half breaths a minute. He notes that prayers and chants in many traditions fall into nearly the same rhythm. Breathing should also be light rather than deep, and done through the nose. Even five or ten minutes a day can help.
Why does carbon dioxide matter in Breath?
Nestor explains that carbon dioxide helps oxygen detach from red blood cells and widens blood vessels so they carry more blood. Fast, heavy breathing expels too much of it, reducing blood flow, which is why panic or hard exercise can cause headaches and light-headedness. Slow breathing keeps more carbon dioxide in the system. Extreme methods that push its level very low or very high can even change consciousness.
Who should read Breath?
It suits anyone who feels stressed, sleeps poorly, snores or breathes through the mouth, and anyone curious about the science behind yoga, meditation and methods like Wim Hof’s. The practical tools are simple, from resting the tongue on the roof of the mouth to timed slow breathing. Nestor also warns that extreme techniques such as forceful breathing are controversial and should not be taken up lightly.
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