I’ve been practising various forms of breathing exercises for about 30 years now. They are the foundation of all my training, to the point that literally every exercise of any kind is always first and foremost a breathing exercise for me. You can see that in this recording of last Friday's trainalong class: the topic is hips, but it's all breathing really:
I’ve written a short training guide on breathing (which is included in Theory and Practice of Historical Martial Arts, and created a whole online course for it (bundled in with the Solo course). And I still learned a lot from James Nestor's Breath. Go buy it, read it, it’s one of those no-brainer must-reads. (All book links are affiliate, so I get a small commission if you buy them. It costs you nothing.)
In essence, the book covers Mr Nestor’s odyssey through the sometimes strange, sometimes wonderful, always interesting, worlds of breathing practice, starting with that age-old question- nose or mouth?
Of course you should breathe through your nose. Practically no exceptions, if the nose is available. But he has his nose plugged and does mouth-only breathing for ten days to find out what the consequences are- and they are really, profoundly, horrible. This is in the best tradition of self-experimentation. He has suffered so we don’t have to.
Unlike most books on the subject, and unlike most practitioners, Mr Nestor also looks at sinus and airway architecture and its importance for good breathing. He takes his study into dentist’s offices, the catacombs under Paris (looking at old skulls), and goes into detail about why our jaws and palates are smaller than they should be, and what to do to change that. Fun fact: though it’s often stated that you can’t add bone mass over 30, you absolutely can add bone mass in your face at pretty much any age. Nestor proves it by actually doing it, with medical scans before and after.
I won’t go into all of the breathing practices he does cover, suffice to say it’s a lot, and some I’d never heard of before. He highlights the work of people like Katharina Schroth, and Alexandra David-Néel, who have been mostly forgotten now but did amazing things with breath as recently as last century. Most interestingly for me, he goes in depth into Tummo breathing, the origin of the Wim Hof method which I practice most days.
I do have three minor caveats.
Firstly, he does the classic page-turner trick of getting half-way into a story then switching to another story, before circling back. It’s annoying to me, because I didn’t need the extra incentive to keep reading. This is a generally a well written, well researched, and utterly fascinating book about one of my core interests. It didn’t need the help. I understand why editors insist on such things but I found it intrusive.
Secondly, though he does describe a lot of anthropological studies and a lot of European, Russian, Indian, Tibetan and American breathing experts and practices, he skips right over the Chinese! Qigong gets a passing mention on page 188, but that’s it. It’s an odd lacuna. It feels to me like there’s a chapter missing. Perhaps he’s working on a follow-up volume dedicated entirely to qigong?
Thirdly, and most importantly, you need to watch out for the condition I think of as “popular science-itis”, which can be summarised as a) making unverifiable claims, b) imprecise use of language leading to misleading statements, and c) overstating the evidence.*
a) describing a breathing technique as “a calming practice that places the heart, lungs, and circulation into a state of coherence” (p 221). What, exactly, is that supposed to mean? And how do you test it? There are similar descriptions of unverifiable effects elsewhere in the book, but to Mr Nestor’s credit he usually sticks to more verifiable/falsifiable statements.
b) “The body has switched from anaerobic to aerobic respiration”, when what I think he means is that specific muscle fibres have switched: the body as a whole (and especially the brain) would have been generally respiring aerobically the whole time.
c) Extrapolating more general conclusions than a specific study might warrant, or stating things in too-conclusive terms, such as “mouthbreathing was making me dumber”, a remark based on a single study done in rats regarding problem solving, and one in humans regarding oxygen supply to one part of the brain (p30). As a description of subjective experience it would be fine (“I felt that mouthbreathing was making me dumber”), or a more qualified statement to introduce the interesting research would also have been fine (“mouthbreathing may have been making me dumber”).
He’s generally very good about such things, and he is having to balance telling a gripping story (that’s the “popular” bit in “popular science”) with getting the science across. This is not an easy trick to pull off, and he does an excellent, if not perfect, job. As with anything health-related, take what you read with a grain of salt, and go read the original studies before betting your life on their conclusions.
But, and this is a huge but: there are so many things in the book that every human should know, and so many practices that you can simply and safely try for yourself, that you’d be a fool not to read it. Go! Even if you think you're already an expert, go. And if you know nothing about breathing, go still faster. I'm certain you won't regret it.
*and let the record state that I fall into the same three traps rather more than I should!