# Breath by James Nestor Source: https://thegisthub.com/books/breath-by-james-nestor Last updated: 2026-11-06 Published 2020 · 304 pages · ISBN 9780735213616 · Categories: Health and the body, Self-improvement A journalist tests ancient and modern breathing methods on himself and argues that how we breathe, through the nose, slowly, and less, shapes sleep, blood pressure, and mood. ## The gist James Nestor argues that most people breathe badly: through the mouth, too fast, and too much. In a Stanford experiment he plugs his nose for ten days and watches his blood pressure, snoring, and sleep apnea get worse, then recover when he switches to nasal breathing. He traces mouth breathing to soft modern food and shrinking jaws. His core prescriptions are to breathe through the nose, slow down to about **5.5 breaths per minute**, tolerate more carbon dioxide (the **Buteyko** method), chew hard food, and exhale fully. He also reports on intense practices such as Tummo and Holotropic Breathwork. Reviewers note that some of his evidence is thin. ## Key ideas ### 1. Mouth breathing measurably harms the body In a Stanford experiment supervised by the rhinologist Jayakar Nayak, Nestor blocked his nostrils for ten days. His blood pressure rose, his snoring went from minutes to hours a night, his sleep apnea events multiplied, and his nasal passages became inflamed. When he switched to nasal breathing for ten days, the numbers reversed. He presents this as a demonstration with a sample of two, not a trial, but uses it to argue that mouth breathing is a hidden cause of poor sleep and high blood pressure. ### 2. The nose does work the mouth cannot Nasal breathing filters, warms, and humidifies air. The nasal tissues produce nitric oxide, which widens blood vessels and raises oxygen uptake. The nose also slows and pressurizes each breath, which improves gas exchange. Nestor describes the nasal cycle, in which the nostrils alternate dominance over the day, and tissue in the nose that swells with congestion. His simplest tactic is mouth taping at night: a small strip over the lips that forces nasal breathing, which he reports cut his own snoring. ### 3. Soft food shrank the human jaw and airway Nestor examines skulls in the Morton Collection at the University of Pennsylvania and in the Paris catacombs. Older skulls have wide jaws, straight teeth, and large nasal openings. Modern skulls are narrower with crowded teeth. Following the dentist Weston Price, he argues that industrial soft food removed the hours of chewing that built the jaw, so the airway narrowed and mouth breathing increased. His fix is to chew more: tough foods and gum, which some studies link to jaw bone growth even in adults. ### 4. Breathe at about 5.5 breaths per minute Luciano Bernardi's research found that reciting the rosary or a yoga mantra slowed breathing to about six breaths per minute and put heart rate, blood pressure, and brain blood flow into a shared rhythm. Nestor calls this coherence and names a perfect breath: inhale for about 5.5 seconds and exhale for about 5.5 seconds. He argues that many prayer traditions converged on this rhythm by accident. Most people breathe at 12 to 20 breaths per minute, which he considers far too fast for calm. ### 5. Breathing less raises carbon dioxide, which delivers oxygen The Bohr effect means carbon dioxide in the blood helps hemoglobin release oxygen to tissues. Overbreathing blows off carbon dioxide, narrows blood vessels, and makes oxygen harder to use. The Ukrainian physician Konstantin Buteyko trained asthma patients to breathe less and reported fewer attacks. Nestor adopts the control pause, the time you can hold your breath after a normal exhale before the urge to breathe, as a rough marker of breathing health. He argues that a full exhale matters more than a deep inhale. ### 6. A full exhale can restore lung function Carl Stough was a choir director who taught emphysema patients in a veterans' hospital to exhale fully and to move the diaphragm again. Many improved enough to leave their beds, and he later coached Olympic runners with the same method, which he called Breathing Coordination. Nestor uses Stough to argue that lung capacity is trainable at any age and that the diaphragm, not the chest, should drive breathing. The practical exercise is to exhale slowly while counting aloud until the air runs out. ### 7. Intense breathing can stress the body on purpose Tummo, a Tibetan practice of forceful breaths and holds, generates heat; Alexandra David-Néel reported seeing monks dry wet sheets with it. The Wim Hof Method is its modern form, and a Radboud University study found that trained volunteers suppressed an immune response to an injected toxin. Holotropic Breathwork, created by Stanislav Grof after LSD was banned, uses an hour of fast breathing to produce altered states. Nestor argues these methods work by pushing the nervous system hard and then letting it recover, not as daily tools. ### 8. Shut your mouth, slow down, exhale fully Nestor's appendix condenses the book into techniques: alternate nostril breathing, Stough's breathing coordination, resonant breathing at 5.5 seconds in and out, Buteyko reduced breathing, chewing, box breathing, and 4-7-8 breathing. His one-line rule is to breathe through the nose, breathe slowly, and breathe less. The example he gives is a person who tapes the mouth at night, practices five minutes of slow breathing a day, and eats harder food, with results showing in snoring and blood pressure within weeks. ## Questions this book answers ### What is Breath by James Nestor about? Breath argues that most people breathe badly: through the mouth, too fast, and too much. Journalist James Nestor tests this on himself in a Stanford experiment, traces mouth breathing to soft modern food and shrinking jaws, and recommends nasal breathing, slow breathing at about 5.5 breaths per minute, and Buteyko-style reduced breathing. ### What happened in the Stanford mouth-breathing experiment in Breath? Nestor and breathing coach Anders Olsson plugged their nostrils for ten days under the supervision of Stanford rhinologist Jayakar Nayak. Nestor's blood pressure rose, his snoring and sleep apnea got worse, and his nasal passages became inflamed. Ten days of nasal breathing reversed the changes. The test had two participants and no control group. ### Why is nose breathing better than mouth breathing according to Breath? Nestor explains that the nose filters, warms, and humidifies air and releases nitric oxide, which widens blood vessels and improves oxygen uptake. Nasal breathing also slows the breath and keeps the airway from drying out, which reduces snoring. He reports that mouth taping at night cut his own snoring. ### What is the 5.5 breathing technique from Breath? Nestor calls it the perfect breath: inhale for about 5.5 seconds and exhale for about 5.5 seconds through the nose, which gives about 5.5 breaths per minute. He bases it on research by Luciano Bernardi showing that prayers and mantras slow breathing to about six per minute and put heart rate and blood pressure into a shared rhythm. ### Is the science in Breath reliable? Reviewers say the science is uneven. The Stanford experiment had two participants, and several claims rest on small studies, animal data, or anecdotes. The links between soft food, skull shape, and mouth breathing are debated. The benefits of nasal and slow breathing for relaxation have better support than the stronger disease claims. ## Full summary ### The argument James Nestor is a science journalist. Breath grew out of a breathing class that a doctor recommended for his recurring pneumonia, and out of his earlier reporting on freediving, where he met people who held their breath for minutes at a time. He came to believe that breathing is a neglected lever on health. His claim is that modern humans breathe through the mouth, too fast, and too much, and that this contributes to snoring, sleep apnea, high blood pressure, anxiety, and crooked teeth. The book mixes three strands. The first is a self-experiment at Stanford. The second is history and anthropology: skulls, lost texts, and forgotten researchers. The third is a tour of breathing practices, from yoga to Wim Hof, that Nestor tries himself. Nestor calls breathing a lost art. His point is that the knowledge was never secret. Ancient Chinese medical texts, yoga manuals, and 19th-century writers such as the painter George Catlin, who urged Americans to shut their mouths and breathe through the nose, all described it. Modern medicine, in his view, treats breathing as automatic and therefore ignores it. He estimates that a large share of adults breathe through the mouth at least part of the time, and that most have never been told it matters. ### The Stanford experiment and the nose Nestor and a Swedish breathing coach, Anders Olsson, agree to a two-part test under the supervision of Jayakar Nayak, a rhinologist at Stanford. For ten days they block their nostrils with silicone plugs and tape so they can only breathe through the mouth. For the next ten days they breathe only through the nose and practice slow breathing exercises. The mouth-breathing phase goes badly for Nestor. His blood pressure rises. His heart rate variability drops. He snores for hours each night, and his sleep apnea events multiply. He feels foggy and anxious. Nayak's team finds that his nasal passages become inflamed and colonized by bacteria. He describes it as feeling sick without being sick. In the nasal phase the numbers reverse. Snoring falls sharply and apnea events almost disappear. Blood pressure comes down. Nestor uses the two phases as the spine of the book. He presents them as a demonstration, not a controlled study, since the sample size is two. **Why the nose matters.** Nestor explains what the nose does that the mouth cannot. It filters, warms, and humidifies air. Its tissues release **nitric oxide**, a molecule that widens blood vessels and increases oxygen uptake. He cites research that nasal breathing raises nitric oxide levels several times over mouth breathing. The nose also slows the breath, which increases the pressure in the lungs and improves gas exchange. He describes the **nasal cycle**: the nostrils alternate dominance every few hours, which some yoga traditions use to shift arousal. He also covers **erectile tissue** in the nose, which swells with congestion, and the way sleeping position affects it. Mouth breathing, in his account, dries the airway, promotes snoring, and lets the tongue fall back during sleep. Over years it changes the face. He cites the work of the orthodontist Marianna Evans and others who argue that a mouth-breathing child grows a longer, narrower face with a smaller jaw and crowded teeth. He spends time on **mouth taping**: a small strip of tape over the lips at night to force nasal breathing. He reports that it reduced his own snoring and that some dentists and sleep specialists recommend it. He also describes **nasal dilators** and the idea that chronic congestion can be trained away. ### The shrinking face A large part of the book is anthropology. Nestor visits the Morton Collection of skulls at the University of Pennsylvania and the catacombs under Paris. Ancient skulls, he reports, show wide jaws, straight teeth, and large nasal openings. Modern skulls show narrower faces and crooked teeth. His explanation follows the dentist Weston Price and later researchers. For most of human history, people chewed tough food for hours each day. Chewing built the jaw and widened the airway. Industrial food is soft. Infants bottle-fed on formula and children raised on processed food do not develop their jaws, so the airway narrows, the tongue has less room, and mouth breathing follows. Nestor argues that this is reversible to a degree, even in adults. He tries a device that applies pressure to the palate to widen it, and he describes studies in which chewing gum or hard foods increased bone density in the jaw. His practical advice is simple: eat food that requires chewing, and chew more. ### Slow and less The most useful chapter for most readers is about rate. Nestor reports research by Luciano Bernardi, who studied people reciting the Latin rosary and the yoga mantra om mani padme hum. Both practices produce a rate of about six breaths per minute. At that rate, heart rate, blood pressure, and brain blood flow enter a rhythm Nestor calls **coherence**. From this and other studies he arrives at what he calls the perfect breath: inhale for about 5.5 seconds, exhale for about 5.5 seconds, for about **5.5 breaths per minute**. He argues that this rhythm improves oxygen delivery and calms the nervous system, and that it is embedded in prayer traditions across cultures. He also notes that many people breathe at 12 to 20 breaths per minute, which he considers too fast. The second idea is breathing **less**. Here Nestor draws on the Ukrainian physician **Konstantin Buteyko**, who treated asthma by training patients to breathe less air. The physiology is the **Bohr effect**: carbon dioxide in the blood helps hemoglobin release oxygen to tissues. Breathing too much blows off carbon dioxide, which constricts blood vessels and makes oxygen harder to deliver. Buteyko's exercises raise tolerance for carbon dioxide. Nestor describes the **control pause**, a measure of how long you can hold your breath after a normal exhale before the urge to breathe arrives, and reports it as a rough marker of breathing health. Nestor applies this to exercise as well. Olsson has him cycle with the mouth closed. At first it feels like suffocation. Over the nasal phase, his output at the same effort improves, and he argues that athletes who train the nose gain endurance because they use oxygen more efficiently. He ties this to the Bohr effect again: more carbon dioxide tolerance means more oxygen delivered to working muscle. He also profiles **Carl Stough**, a choir director who taught emphysema patients and Olympic runners to exhale fully, and whose method, Breathing Coordination, improved lung function in patients that doctors had written off. Nestor argues that a full exhale is more important than a deep inhale. ### Breathing hard: Tummo, Wim Hof, and Holotropic Breathwork The later chapters move to intense techniques that stress the body on purpose. Nestor calls them "breathing plus." **Tummo** is a Tibetan Buddhist practice of forceful breathing and breath holds that generates body heat. He tells the story of Alexandra David-Néel, a French explorer who reported seeing monks dry wet sheets with their bodies in the cold, and of the French yogi Maurice Daubard, who practices in snow in his eighties. The best known modern version is the **Wim Hof Method**: rounds of deep breaths followed by breath holds, plus cold exposure. Nestor cites a study at Radboud University in which trained volunteers suppressed an immune reaction to an injected toxin. **Holotropic Breathwork** was developed by the psychiatrist Stanislav Grof as a legal substitute for LSD after the drug was banned. Participants breathe fast and deep for an hour or more to music and report visions, emotional release, and altered states. Nestor tries it and reports a mild experience. He also describes **Sudarshan Kriya**, a rhythmic breathing practice taught by the Art of Living Foundation, and visits a researcher who studies carbon dioxide and the fear response in people with anxiety. His position on these methods is that they work by pushing the nervous system hard and then letting it recover. He does not treat them as daily tools for everyone. ### The appendix of techniques Nestor closes with a short list of methods readers can try: - **Alternate nostril breathing** (nadi shodhana): close one nostril, inhale, close the other, exhale, and repeat. - **Breathing coordination**: Stough's method of long, full exhales while counting aloud. - **Resonant or coherent breathing**: inhale and exhale for about 5.5 seconds each. - **Buteyko breathing**: control pause measurements and reduced-volume breathing. - **Chewing**: tough foods and gum to build the jaw. - **Box breathing**: inhale, hold, exhale, hold, each for four counts. - **4-7-8 breathing**: inhale for four, hold for seven, exhale for eight. - **Breathing plus**: Tummo and similar methods, with a warning not to practice them in water or while driving. His summary rule is: shut your mouth, breathe through your nose, breathe slowly, and exhale fully. ### What the critics say Reviewers describe the science as uneven. The Stanford test involved two people and no controls. Several claims rest on small studies, animal data, or anecdotes, and the links between skull shape, soft food, and mouth breathing are debated among anthropologists. The benefits of nasal breathing and slow breathing for relaxation have better support than the stronger claims about disease. Readers should treat the book as a tour of ideas, not a clinical guide. ### Who should read it Read it if you snore, sleep badly, feel anxious, or have never thought about how you breathe. The chapters on nasal breathing and slow breathing are the practical core. Skip the Tummo and Holotropic sections unless you want the history. ## Do this week - Practice resonant breathing for five minutes today: inhale for about 5.5 seconds and exhale for about 5.5 seconds through the nose. - Measure your control pause tonight: exhale normally, hold, and time how long until the first urge to breathe. - Try a small strip of medical tape over your lips for one night this week and note whether you wake with a dry mouth. - Replace one soft meal this week with food that takes real chewing, such as raw vegetables, nuts, or tough bread. - Do one minute of long exhales while counting aloud until you run out of air, then repeat three times. Summary by The Gist Hub (https://thegisthub.com). In our own words, not the book's text.