The Science of Yoga: The Risks and the Rewards

by William J. Broad

A lead science writer for The New York Times —and lifelong yoga practitioner—examines centuries of history and research to scrutinize the claims made about yoga for health, fitness, emotional wellbeing, sex, weight loss, healing, and creativity. He reveals what is real and what is illusory, in the process exposing moves that can harm or even kill.

Five years in the making, The Science of Yoga draws on a hidden wealth of discovery, drama, and surprising fact to cut through the fog that surrounds contemporary yoga and to show—for the first time—what is uplifting and beneficial and what is delusional, flaky, and dangerous. At heart, it illuminates the risks and rewards.

Broad describes yoga as a burgeoning global industry that attracts not only curious scientists but millions of true believers and charismatic hustlers. He takes the reader on a whirlwind tour of unknown yoga that goes from old archives in Calcutta to world capitals of medical research, from storied ashrams to spotless laboratories, from sweaty yoga studios with master teachers to the cozy offices of yoga healers. In the process, he shatters myths, lays out unexpected benefits, and offers a compelling vision of how the discipline can be improved.

Genres: Nonfiction, Science, Health, Fitness, History, Spirituality, Self Help

298 pages, Hardcover

First published January 1, 2012

About the author

William J. Broad is a best-selling author and a senior writer at The New York Times. In more than thirty years as a science journalist, he has written hundreds of front-page articles and won every major journalistic award in print and film. His reporting shows unusual depth and breadth—everything from exploding stars and the secret life of marine mammals to the spread of nuclear arms and why the Titanic sank so fast. The Best American Science Writing, a yearly anthology, has twice featured his work.

He joined The Times in 1983 and before that worked in Washington for Science, the magazine of the American Association for the Advancement of Science.

Broad has won two Pulitzer Prizes with Times colleagues, as well as an Emmy and a DuPont. He won the Pulitzers for coverage of the space shuttle Challenger disaster and the feasibility of antimissile arms. In 2002, he won the Emmy (PBS Nova) for a documentary that detailed the threat of germ terrorism. He was a Pulitzer finalist in 2005 for articles written with Times colleague David E. Sanger on nuclear proliferation. In 2007, he shared a DuPont Award (The Discovery Channel) from the Columbia University Graduate School of Journalism for the television documentary, Nuclear Jihad: Can Terrorists Get the Bomb?

Broad is the author or co-author of eight books, most recently The Science of Yoga: The Risks and the Rewards (Simon & Schuster, 2012), a New York Times bestseller. His books have been translated into dozens of languages. His other titles include Germs: Biological Weapons and America's Secret War (Simon & Schuster, 2001), a number-one New York Times bestseller; The Universe Below: Discovering the Secrets of the Deep Sea (Simon & Schuster, 1997); Teller's War: The Top-Secret Story Behind the Star Wars Deception (Simon & Schuster, 1992); and Betrayers of the Truth: Fraud and Deceit in the Halls of Science (Simon & Schuster, 1982).

Broad's reporting has taken him to Paris and Vienna, Brazil and Ecuador, Kiev and Kazakhstan. In December 1991, he was among the last Westerners to see the Soviet hammer and sickle flying over the Kremlin.

Broad's media appearances include Larry King Live, The Charlie Rose Show, The Discovery Channel, Nova, The History Channel, and National Public Radio. His speaking engagements have ranged from the U.S. Navy in Washington, to the Knickerbocker Club in New York, to the Monterey Aquarium in California. He has also given talks at the Corcoran Gallery of Art in Washington, D.C. and the Council on Foreign Relations in New York City.

Broad earned a master's degree in the history of science from the University of Wisconsin at Madison. He has three adult children and lives with his wife in the New York metropolitan area.

Reviews

[Andrew Gray · Rating 4 out of 5]

As a yoga teacher, I have been surrounded by negative energy from the yoga world about Mr. Broad. His articles in the NY Times have garnered lots of attention and have royally pissed people off. The book itself, though, is generally positive about yoga. The only thing it really states definitively is that yoga doesn't qualify as cardiovascular exercise. A friend said, "Well, this guy hasn't done 108 sun salutations in a row then -- I promise that is cardiovascular exercise!" If doing 108 sun salutations in a row is what yoga is, I don't want anything to do with it. 108 sun salutations in a row is hell -- yes, I have done that before . . .

This book got me thinking and confirmed a lot of things I had suspected. For example, pranayama doesn't change the amount of oxygen in your blood, it changes the amount of CO2. Lots of yoga teachers talk about increasing the O2 when science taught us long ago that a normal person, without even trying, is oxygenating at 99-100%. You can't go higher than 100% . . .

I also liked reading the history sections. I love that there is this huge "sex cult" aspect that people tend to gloss over when they speak about yoga's "5000 year history."

In short, I wish there were a way to get every yoga teacher in America to read this book, but, alas, I am afraid most will run from it screaming . . .

[Tim Gunderson · Rating 5 out of 5]

The perfect antidote to yoga rage,

I would call myself a rational, realistic person who is skeptical of wide eyed, exaggerated flavour of the month fitness and nutrition health claims. I've also been practicing yoga for over 13 years now. Therefore, it has frequently been a challenge for me to reconcile the inherently flaky, faux spirituality present in any urban yoga studio with the quite obvious reality that there are clear physical and mental benefits to practicing yoga.

This book lays out the history of where yoga came from, from its sideshow cult like beginnings, to its discarded role in the Indian independence movement which laid the ground work to the sanitized western incarnation. William J. Broad expertly contrasts scientifically measured benefits with the various claims made by the yoga elite and takes a as well as the risks and falsehoods present in western yoga. Broad's writing is concise, yet rigorous, going far beyond the "Top 20 ways to burn away belly fat with Yoga" nonsense that you see on the cover of fitness magazines to the true benefits of the practice.

Unfortunately, yoga is not the magic bullet to perfect health, but it is the perfect compliment to a regular cardiovascular work out. It has been shown to slow the aging process, and perhaps most importantly, to improve practitioner's happiness and sense of well being.

This book is a great read for any yoga skeptic with an open mind.

[Jokoloyo · Rating 5 out of 5]

This is a good introduction book to the science of yoga-related activities. I recommend yoga enthusiasts to read it. This book is not perfect, maybe far from it, but it gives you precautions about yoga activities. Yes, there are discussions about benefits of yoga, but I believe if you have heard the benefits from many other sources.

In my opinion, the heart of this book is on "risk" parts as we can read on Fit Perfection, Risk of Injury, and Healing chapters. Those chapters have a lot of research materials that we can check later. Unfortunately Divine Sex Chapter and Muse Chapter on later "reward" parts of the book are not researched as deep as previous chapters. Especially Divine Sex, filled with information that unrelated to Yoga directly, and then without satisfying conclusion (for me), author just end the chapter.

I like the epilogue and viewing current state (early 21st ce) as in Yoga 2.5 phase. I have similar feeling could not define the idea of phase. Thanks to this book, I have one less irritating thought.

But even with the flaws, I still rate this book as 5 star, for the warning value. Too many cases (even from my personal experience) where yogi and yogini focus on the reward blindly without considering the risks, or following every yoga lesson/teaching without proper criticized mind. This book can open your mind with modern yoga world.

[Sian Lile-Pastore · Rating 1 out of 5]

This book is dreadful. Mainly it's just badly written - like a super long magazine article. There are many things I hated about this book, so much that I can't be bothered to go into all of them....
But here are some things that particularly annoyed me:

Injuries - there's a lot about how dangerous yoga is but in the afterward he admits that more people get injured playing golf or weightlifting. He also talks about how you can get a stroke from tipping your neck back really far in cobra (or getting your hair washed at a salon apparently) which y'kno, I'm sure you can - but actually I've never been to a class that teaches tipping your neck back so am not sure how relevant this is. Sure you can get injured doing yoga (like any exercise) but I think these severe injuries he's talking about are when the student is really advanced and also pushing themselves too far.
He also talks about someone getting an injury when they FELL ASLEEP in a forward fold!! Who falls asleep in a forward fold?? I'm not taking this shit seriously!

Sexism - generally he's a big sexist, the people he takes seriously are older guys, he's dismissive of 'former model Tara Stiles' and 'gushing' elizabeth Gilbert.

The sex chapter is really bad. Tantra doesn't mean sex.

Generally, I felt that even tho the author practices yoga, I didn't feel he really understood it. I think that if he'd had done a yoga teacher training course as part of his research he'd have had a better understanding and also seen that training DOES discuss injuries, modifications, anatomy and science.

This book was written in 2012, surely we've moved on from talking about Sting and what they said about yoga in an episode of Sex and the City? And also things aren't science just coz you start a sentence saying 'science says that...'

[Katrina · Rating 3 out of 5]

So, here's the book that has caused all the controversy. Oooooo. Ready? Okay, Broad is not a great writer. He's biased; and gives lots of his own opinions in a "scientific" review of evidence. So that didn't impress me. However, a lot of what he has to say is very good. Yoga CAN be dangerous. That's why students need to vet their teachers, their studios and the flavor of yoga that they choose to practice. Yoga is NOT going to burn tons of calories. You want cardio, do cardio. Yoga's contribution to weight loss and overall health is far more subtle.....and FAR more powerful - it's total transformation. Broad's narrative highlights recent findings on yoga and its significant impact on depression, trauma, immunology, longevity.... and these are all much more impressive to me than getting a 'yoga butt.' So, Broad's overall message is a good one. The yoga industry is at an important cross roads. And those of us who are part of the yoga movement need to decide whether or not we want it to move forward alongside science (check out Kripalu's Institute for Extraodinary Living)or keep it as some sort of mystic panacea. If you're interested in yoga, you should be interested in this book......so long as you can overlook some (at times) serious editorializing in the name of reporting.

[Ci · Rating 4 out of 5]

Yoga books are mostly two categories: colorful instruction manuals, or text based on ancient or modern philosophy. Personal anecdotal narratives abound, but what about something to analyze the objective experiences? Naturally, yoga is not about objective experiences, it is largely a personal experience outside of pure fitness realm. Yet given how yoga is being marketed, would it be worthwhile to quantify the things that we can objectively measure such as various health acclaims measurable through biomedical measures? Subjecting yoga to such examination does not negate its other aims or claims, it simply asks for the evidences where evidences are producible and potentially information.

Very few books are evidence-based, or scientifically based. But this is a serious book aiming exactly at that -- to search and examine the body of evidences on various yoga claims. The author also makes valuable judgment of the quality of the studies (such as a controlled, double-blinded, large sample study with clear objectives and measurements is better than a ex-post observational study with a few individuals and vague questionnaires). He pointed out where science can have some answer -- no, yoga does not increase your metabolism, it actually lowers it -- but also the area we still don't have a clear picture (such as impact on creativity).

The most "shocking" part is about yoga injuries. Injuries in yoga is a taboo issue; it is something the sufferers often have to endure silently without questioning the basic premises of human physiology, largely because yoga is supposedly to be "healing" and "safe for everyone". In addition, as yoga is marketed toward the urban affluents (such as in cities like NYC, DC, etc), yoga is combined with a keen direction toward aesthetics and fitness. No wonder the competitive spirit is sold along with yoga in such settings. Yoga injury is just another sport injury -- people push too hard on their bodies, something goes wrong -- just like anything else. The label of "yoga" is not going to prevent us from tearing our muscles or tendons, or pushing our bones or joints out of their own limits.

This is a very well-researched book for anyone interested in yoga.

[Amy · Rating 3 out of 5]

Dana Carvey has a bit in a recent stand-up routine about how after a certain age (an earlier age than you expected), you can seriously injure yourself just reaching for the TV remote. "The Science of Yoga" presents the usually unmentioned risks to yoga.

Not a really controversial thesis here. As with any other exercise, you can hurt yourself. As with any other exercise, you can improve some aspects of your health.

Certain yoga poses might cause neck strain--check, not new information. Those same poses might cause a stroke--wow, new information! Also new information: that I could get a stroke having my hair washed at a beauty parlor (not sure about barber shops).

The book's "scare" chapter (about strokes, etc.) left me with mixed emotions. Naturally, I went to a 90-minute Bikram yoga class to work them out. On the one hand, I'm glad the author reminded me to pay attention, practice mindfully, and keep ego (mine, my neighbor's, a teacher's ego) from pushing me into doing something stupid.

On the other hand, I'm unsatisfied by the author's mix of data and anecdotes to prove his points. Long-time yoga practitioners often tell pretty tall tales. They can make my grandpa's fishing stories look understated. So I'm skeptical of the results from yoga teacher surveys, and I don't for a second believe a yoga practitioner broke three of his own ribs doing a spine twist.

I also wish the author, in that chapter, had set more context for his conclusions about yoga's risks. How do these risks compare to the risk of throwing a blood clot on a trans-oceanic flight? To the risk of repetititive stress injuries in running, golf, racquetball, i.e., other sports popular with the same types of people who buy yoga studio memberships?

Good way to get people talking, fair to point out that yoga isn't magical. But will this book, or the publicity around it, frighten some people from trying yoga?

Will update the review when I've read more than the scare chapter and the introductory chapter (which frames yoga practice in a history of yogis as India's social deviants...sigh).

[Stephanie · Rating 2 out of 5]

2.5 stars. This book started out very strong and then took a long, graceful, smoking, flaming nosedive. Broad started off very skeptical, digging into the science and laying out for me exactly what was true and what was not with regard to Yoga's most famous claims—the abilities to stop the heart and to increase oxygen intake, primarily. He even explained the different scientific journals and schools that did studies on Yoga, their types, their sources of funding, and what that meant for the credibility of each one. I greatly appreciated this. I thought the fiery passion with which he debunked The Complete Idiot's Guide To Yoga was great, if a little weird. The first two sections of the book, Health and Fit Perfection, were pretty darn good and useful and informative, and after that each section was progressively worse than the last.

In Moods the facts were kind of all over the place and not as well presented. Risk of Injury all but neglected the more common Yoga injuries and instead focused on the relatively minute risk of stroke—and yet pretty much failed to advise the reader on how to avoid this risk. The Healing chapter was pretty terrible in that it focused on two individuals who use Yoga to heal, one successfully and one less so. Let's hear about the science of it, eh? And if there isn't any, then why is it in this book? The Divine Sex chapter was TMI, in my opinion. Some people's ability to "think off" should've been mentioned briefly in the Mood section and left at that. I really didn't need to spend that much time hearing about it. Kundalini is a weird little fringe Yoga cult that i frankly don't care about. And here again Broad didn't actually discuss the science of it. How do they do it? What's the benefit? Why should i care? Even after that chapter, i was yet again surprised by how awful the Muse chapter was. There was nothing even remotely scientific about this chapter. Broad made a very weak argument that Yoga stimulates the right hemisphere of the brain and therefore probably definitely makes people more creative. And then he talked about a group of people who get together to share their god-awful poetry that Yoga inspired them to write. Yikes.

And finally, the book explodes in a great plume of flaming wreckage as the author declares in the Epilogue that he doesn't think science can tell us anything meaningful about Yoga. I can only assume that this is the reason that he never once even mentions the whole concept of "prana"; he must think it's some mystical thing that science knows nothing of. Well if it affects our physical body, then science should be able to study it if it exists—period. I had high hopes at the outset of this book that it would take a strictly scientific approach to Yoga, but it wandered way off track. It failed to advise me on how to make my Yoga practice better, failed to entice me to practice Kundalini, and failed to even begin to explain to me what the heck all that chakra bullshit is about. I'd say it's quite disappointing.

[Liz Dean · Rating 3 out of 5]

Basic findings from scientific research presented in this book:
1- Yoga does not improve cardivascular fitness.
2- Yoga is likely to cause you to gain weight, rather than lose it, because it decreases your metabolism.
3- Yoga significantly improves symptoms of anxiety and depression, across the board.
4- Yoga measurably, vastly improves your libido and sexual function.
5- Your brain on yoga, as measured by MRIs, is like your brain on spiritual inspiration and orgasm.

So don't do yoga to get in shape, physically, BUT - do it for all the other reasons. The evidence is there. It's a fascinating read.

[Emily · Rating 5 out of 5]

The health benefits of yoga has been praised over the years, but it bothered me that there was a lack of hard science behind a lot of the claims. This is not a salacious debunking of yoga's health benefits, but a very even-handed, well-researched examination of the history of yoga, and an even deeper look into specific studies and tests that have been done to understand the benefits of yoga.

There was a big hoopla on the NYT in January 2012 on how this book warns of the dark dangers of yoga. Broad covers a lot of depth, and it's easy to dismiss it as scaremongering – if you don't read the entire book. He also looks at the rewards of yoga, some measurable by science, some not. (The chapter on how yoga affects sex is especially interesting, for obvious reasons, and if you have ever done yoga for quite some time, makes a lot of sense...) What's most stunning is not so much the "yoga myths" that Broad demystifies, but how his work reveals what little research has actually been done on benefits and dangers of yoga – a valid concern given how big of a business it's becoming. Excellent read that anyone who has ever practiced yoga or is thinking about practicing yoga should look into.

[Natalie · Rating 4 out of 5]

It was rage that caused me to purchase this book. Well played, New York Times.

After such riling and aggrevating headlines such as "How Yoga Can Wreck Your Body" and "Yoga and Sex Scandals: No Surprise Here," I needed to get to the bottom of what this man William Broad was talking about in his Science of Yoga.

Broad states that "a synomym for science is organized skepticism". And so with a fire in my belly, I opened his book.

Although I found his tone to be somewhat sanctimonious and sexist, like a 1950's TV dad "tsk-tsk"-ing his children, a lot of what Broad had to say opened my eyes to how I'm leading my yoga classes.

One of the claims he puts to rest immediately is how yoga improves oxygen intake and floods the bloodstream with fresh oxygen. He also disputes yoga's claims to be the sole method to become physically fit. Broad cites a study done at the University of Wisconsin in which women with no prior yoga experience were studied as they did 55 minutes of Hatha three times a week. Unfortunately, according to the study, the women showed "gains in strength, endurance, balance and flexibility, but not in VO2 max (oxygen consumption)." Therefore, not an aerobic workout.

It's inconvenient as a yoga teacher to read these claims. But they also ignited a desire inside me to learn more about exactly what is going on in the body during yoga asanas, pranayama, and the like. It was also inconvenient and confusing for me to read in one chapter how headstands can kill you and see them suggested to heal a rotator cuff injury in the next chapter.

All in all, I believe this book is a challenging but important read. There are a few postures that I will avoid teaching until I learn more about what happens in the body. And there are new ideas I will explore such as Kundalini and how the right brain is affected by yoga.

I would like to see a greater understanding of the science of yoga. I feel that with so many claims out there about one style being better than another, a little science can't hurt. I would like to see yoga as an alternative to pills for dealing with stress, high blood pressure, insomnia and other first world afflictions.

At the end of the day, I think a mindful practice with an attentive, knowledgeable teacher is the best way to ensure you're providing yourself with the safest approach to yoga.

[Olga · Rating 5 out of 5]

A balanced view.

[Randal · Rating 5 out of 5]

William Broad has done an excellent job with gathering the scientific reports and synthesizing an intelligent review of modern yoga. The 'scientific' platform turns out to be a `must have' prop for improving our understanding and practice of yoga.

The book situates modern yoga, the physical and scientific endeavor, as a development to promote Indian nationalism in the mid-nineteenth century. In an early and startling scientific disappointment - even with the recent tinkering of adding Sun Salutations and developing the faster moving vinyasa styles - yoga fails to meet standards of aerobic challenge - the gold standard for fitness evaluation - set by the American College of Sports Medicine. With that case closed - Yoga builds recognition for significant findings in important areas such as uplifting mood, rejuvenating endocrine function, improving creativity, fortifying longevity, improving balance, reducing fatigue, decreasing anxiety, cutting stress, improving sleep, reducing pain, lowering cholesterol and more generally in raising the quality of life for yogis both socially and on the job. In an ironic twist the study of yoga as a physical form returns us to wondering about its more subtle and uplifting benefits.

Along the way the author blazes an impressive path in reviewing yoga's impact on the subtle science of respiration. As well as injuries that relate mostly to joints and subsequently to vital circulation connected with risk of nerve damage and stroke. The findings suggest that the faster styles of yoga raise the risk of injury - a 2009 study in Europe reports that over 60% of Ashtanga practitioners have sustained injuries lasting more than one month. Noting the rising concern the author cites more than a few hero's in the field that are making strides to effectively address the issues. I found his critical review to be most helpful in refining and validating my own approach.

The text develops its climax in the well paced recognition of yoga's right brain activation and subsequent limbic stimulation. This is the neurological pathway to improving the information processing of primal experience akin to raising the inner fire. Central to this development is the yoga paradox which is that certain exercises promote hypo-metabolism while others ignite hyper-metabolism. These two extremes refine homeostatic inquiry and plays a key role in yoga as wellness.

Yoga is everywhere - from the white house lawn on Easter to fringe sub-cultures on retreat in the forest. One interesting thing I noted in this text is that the studies come from all over the world. The technology that sprang from India resonates with the interests of researchers in the United Kingdom, Taiwan, Russia, Italy and the United States to name a few. The timing of this text is perfect and opens up an important conversation.

He concludes that the `science of yoga' is just beginning and if yoga is to evolve to meet the challenges of a modern world let alone discover its own potential then the scientific method will be among its greatest allies. That said there are certain challenges and limits to acknowledge when science meets yoga:

(1) funding for objective research does not match its proven potential as a cutting edge and low-cost, low impact alternative therapy

(2) there is no central and appropriately funded governing body to organize yoga or yoga therapy let alone coordinate an effort to systematically investigate the exercises - a big question emerges and everyone should be asking: 'Why was this critical review of the science of yoga not already organized and widely available inside the yoga profession?

(3) yoga teachers can be certified but undertrained to meet many of the challenges associated with healthcare let alone understanding their own practices and professional responsibilities - in a 2009 report 68% of 1300 YT's surveyed agree that there needs to be higher training standards if we are to reduce injuries

(4) yoga is highly subjective and has been difficult to study but the tools are improving rapidly

(5) no study has so far identified what yoga is in their operating definition and it continues to exist that yoga can be many things to many people

(6) modern yoga is a billion dollar industry with `economic rationalizations' and 'spreadsheet ethics' with no oversight regulating as to its dispensation and sales appeal

Constructive Criticism

My main concern with the text is that Broad is not a professional yoga educator. He is a talented, accomplished writer who is thus well situated to observe from afar. However, from my seasoned insider's perspective, the current text could be significantly enhanced with more expert input.

Broad defines the roots of modern yoga as the Hatha Yoga Pradipika, Tantric sex cults, and the Indian nationalist movement. These are true artifacts but in editing out approximately 4,000 years of texts and culture prior he loses significant ground work - including Classical Yoga of Patanjali, Ayurveda - the sister medical science, the poetry of the Upanishads and the technology of fire that is the Vedas - that could inform and illuminate a more robust operating definition of what yoga is and can be.

For example, the author notes that Patanjali's Yoga Sutra 'says nothing of [asana] despite its regular citation as a founding document of postural yoga' (p. xxv). In my reading of Yoga Sutra there are three sutras dedicated to asana and Patanjali is quite clear on his approach as a means of realization (book 2.46-28). To read in the opening pages of Broad's text that Patanjali YS are irrelevant to modern postural yoga is erroneous but understandable given the limits of understanding in the scientific inquiries based on the physicality of yoga.

Science plays the hero in this text but in truth its methods and tools for examining subjectivity have only just begun to improve in recent years. No one in the field knows exactly what yoga is in the first place so each investigator can define it in their own terms and pull yoga in any number of directions to achieve any goal. But where is it truly rooted? The field is exciting and fertile for this very reason. The operating definition of yoga needs to be the focus of a future review.

Broad's bio states he has been a yoga practitioner since the 1970's. And his current text is a significant addition to the field that surpasses the existing works of many so-called yoga experts. While a skillful researcher and narrator he sometimes overcasts the villains and heroes. In the Epilogue he proposes the creation of a regulatory body called YES - for Yoga Education Society. Broad's criticism of the existing entity doing that job namely IAYT is implied but never directly expressed. And IAYT as far as I know is a leader doing excellent work with what relatively limited resources it has available. In my opinion it would have been more appropriate to suggest enhancements to such organizations as IAYT that would make a difference.

Broad seems determined to demonstrate his expertise and get deep inside the structure of yoga. His rigid notion of yoga as 'sex' pokes its way into the text over and over and ends coming all over the narrative arc. I agree that there is a meaningful resonance. But would suggest, as Jung did with Freud, that the term `creative force' or `life intelligence' is better suited and more stabilizing as an objective framework to the future inquiries especially in neuroscience related to the science of yoga.

I found this book to be the reflection of major work, an inspiration and educational. It was well worth my time as a practitioner, Kripalu Yoga Teacher and Yoga Teacher Trainer. It has changed the way I work with yoga for the better.

RW

[Katherine · Rating 2 out of 5]

This book wasn't what I expected. I was expecting something easily digested, with short sections and a lot of section headings, or something. This book has a six-and-a-half page cast of characters in the front of the book, so you don't get the names confused.

What I wanted, I guess, was a collection of nuggets of information that were going to help me (I've been practicing yoga, on and off, but medium-seriously at times, for ten years) understand better just what yoga is, how it helps me, and how it can hurt. I mean, that much was implied by the title, right?

There is information about the risks and rewards of yoga here, but Broad doesn't do that great a job, in my opinion, of distilling it down to a bottom line. He's a newspaper-man, and writes like a newspaper-man, while maybe I was expecting the book equivalent of a well-written magazine service piece.

At times, the book seems to delight in the contradictions that can bemuse an average yogi or yogini looking for guidance in her practice. For example, you learn that certain poses (mainly ones with severe neck bending, like shoulder stand and plough) can cause strokes. Strokes! But elsewhere in the book, you learn how very good for you these poses are. So, break it down for me! Should I do shoulder stand, or not?! I know, the choice is mine to make, you have armed me with information, etc., etc.—but I wanted a fun easy read, not a mind-twister where I have to choose between denying myself the benefits of my favorite inversion vs. having a brain attack.

Elsewhere, there was a whole lot of text devoted to certain issues, while others went unexplored. For example, there is an entire chapter that sifts evidence pointing to the conclusion (a conclusion that seems pretty obvious to me anyway) that yoga doesn't do much for your cardiovascular fitness. No duh! But there's nothing about how the poses of yoga sculpt your muscles, for example. It just seemed like a pretty selective account.

There's also a lot of traveling around and speaking to various experts, but few of those journeys are colorful or distinctive enough that they really add value for me. I am willing to bet that the average practitioner of yoga would rather have had Broad take what he had learned and put it into a more reference-book-like format.

That all said, there were some pretty interesting pieces of information suspended int the broth. There's a section debunking the fallacy that yoga revs your metabolism (it lowers it!) There is a section about how the idea that deep breathing 'floods your tissues with oxygen' (and how many yoga teachers have we all heard saying exactly that, over the years?) is dead wrong. I guess I appreciated the stroke warnings, as grim as they were. I didn't expect to be that captivated by the section on sex or the one on moods, but they both had engaging threads in them. Oh, and there's a theme throughout the book about the idea of physical arousal versus calming, and how yoga may do what it does by inducing the body to switch back and forth between these states—that, at least, was a framework that I can take away and contemplate when I'm on my mat.

In writing a book about the science of yoga, Broad faces some baked-in problems that he can't do anything but try to take in stride. The scientific studies of yoga, such as they are, aren't large or well-funded. 'Yoga' in itself is such an amorphous thing (there are many yogas), and they can be practiced well or badly, at so many different levels of intensity, that it's really tough to study or generalize about the effects of "yoga" on a person. If his book feels spotty in its coverage of 'yoga questions' that I came in with, maybe it's because the research itself is spotty.

Maybe the book and I just got off on the wrong foot: the first chapter is about the history of yoga, and I was really looking forward to it, but again it left me with more questions than answers. Or perhaps more accurately, it left me confused about whether yoga is actually an ancient practice or a modern one. It made it sound like there were dudes walking around India doing "yoga" hundreds of years ago, but they were more likely to be drinking blood out of human skulls and asking to get buried alive—it sort of sounded like the whole asanas thing was invented shortly before the drive for Indian independence, which makes it all not even much more than 100 years old, which kind of tended to make me more skeptical about yoga than not.

Two stars seems unnecessarily harsh, I did enjoy passages from this book. I went to a yoga class the day after finishing it, feeling re-energized about yoga's beneficial possibilities. But it also seems to me that there's still room out there for somebody to write a book about yoga that helps to reflect the millions of American yogis back to themselves, and understand what they're doing from a perspective both cultural and physical, and offer them some practical thoughts on how to get the most of it.

[Jasmina · Rating 4 out of 5]

really really informative - but a little too offtopic (imo) and hard to read towards the end. highly recommend for an insight onto the dangers and scientifically proven benefits of yoga!

[Stewart Home · Rating 2 out of 5]

Broad appears to have reviewed a wide range of scientific literature on the subject of yoga but most of the studies appear too small to draw any real conclusions from. Broad sometimes points this out and sometimes doesn't. His history of yoga is what you'd expect from a science journalist, unsatisfactory. The best chapter is the one of Risk of Injury, which is the section of the book that upset the new age true believers in yoga. That chapter seems realistic, elsewhere Broad is way too upbeat about the benefits of yoga; particularly in Divine Sex and Muse. Broad even quotes mock 'musician' Sting and treats him as if he's somehow creative. I can still remember being at a punk gig in London in 1978 and Sting's old group The Police had blagged an unannounced support slot, when they came on the entire audience turned their backs on this worthless crew who couldn't even rock and walked to the bar at the back of the room to wait for the headline act. If yoga aided Sting's 'creativity' then its effects are less than nothing since he doesn't have any. But since Broad has his eye firmly on the bestseller chart he isn't going to be critical of celebrity culture or even yoga. This is a work of popular science and what you see is what you get. Modern postural yoga as taught in gyms throughout the overdeveloped world is a relax and stretch regime, nothing wrong with that, but anyone whose tried it and is also serious about exercise will know that it can't replace regular fitness training. This is more or less what Broad's book will tell you, but you don't need his book or the studies he bases it on to know that.

[Jenny Miller · Rating 1 out of 5]

Here's my review of The Science of Yoga: The Risks and Rewards. Seriously, the guy is not a genius. It's not very well-researched or written. It's nowhere near the standard for investigation or lively-writing we'd enjoy with Michael Pollan, Mark Kurlanksy, or Bill Bryson, for example. He's really excited about sex! And he loves finding anecdotes that support his thesis. Including his own injury, which was caused by running, and which he exacerbated while not paying attention to what he was doing during class. Yeah, I'm a yoga teacher, so I've got opinions. But if you're looking for a good history, try Yoga Body, by Mark Singleton, and if you're looking for posture science, I recommend Anatomy of Hatha Yoga by David Coulter.

[Chris · Rating 4 out of 5]

As the subtitle states, Broad discussed both risks AND rewards of yoga. I enjoyed learning about the history and physiology of postures and breathing. In continuing my own practice I'm also aware and careful especially with regards to my neck. Must read for a broad overview of the recent state of research and potential future of yoga.

[Pili · Rating 4 out of 5]

Really interesting and informative. Rigorous and feels quite impartial, even if the author is himself a yoga practitioner. So much information that I did not know! Very much recommend it if you fall in love with yoga and want to know more!

[Anna Marie · Rating 5 out of 5]

An absolute must read for all serious yoga practitioners and teachers, old and new. Well researched, accessibly written and full of thought provoking content leaving you wanting to read more. Thank you Broad for your balanced accounts of the practice I love so much!

[Is · Rating 3 out of 5]

This book started promising with some history of yoga (styles), a chronology of research on yoga. His exposé on health science on yoga is convincing well written and debunking a lot of the marketing messages found around the world on yoga even 14 years after this book made its debut. However his writings on psychological effects became of lesser quality and then turning towards the end of the book with a lot of quibble on the sex effects of yoga where he forgets to stay focused on the scientific part. And on creativity he missed this completely even emphasizing some myths here. The following last chapters of the book were a waste of my time. However if you want to know the truth about yoga, I recommend you to read this book but stop reading after chapter V.

[Hirondelle (not getting notifications) · Rating 2 out of 5]

It took me ages to finish this (even if I do read non fiction piecewise while reading other things) and frankly if I knew, I would not have bothered past the first couple chapters (or maybe just first chapter). It gets crazier and crazier and more pompous and rambling the further in you get.

I liked the perspective on the history of yoga (but maybe there is a better one over there, this was just the first I read) and the chapter on injuries was interesting. But as it goes along and into benefits, sex, inspiration, Kundalini yoga and so on, it goes crazy very very fast.

Huge bibliography and dozens of people interviewed - which makes for a chaotic read but at least the author gets an A for a lot of hustle preparing this. But for a supposed science journalist, he seems to not get that one article posted somewhere does not irrevocably prove something happens often. Lots more of subjective opinions, fawning about the people interviewed (and totally random nod to Michelle Obama!) and kind of bitchy to "former models". Totally blind to class or wealth issues as well.

A huge mess of a book, which was disappointing because this was something I wanted to learn more about.

[Chelsey Thompson · Rating 3 out of 5]

Overall, this book presented some great research regarding the risks of certain poses, erroneous claims made by yogis, and the potential benefits yoga provides. I enjoyed understanding the science behind how slowing down and speeding up your breath affects the carbon dioxide in your blood and therefore the oxygen to the brain. I also found the reasoning behind the benefits of inversions to be interesting.

However, I think the author was a little too insistent that yoga did not provide a cardiovascular benefit -- though he admits sun salutations do bring you into cardio heart rate ranges. I don't think yoga should be your only cardio activity, however in my experience while wearing a heart rate monitor, classes that are heavy in movement and sun salutations keep you in cardio ranges for a good percentage of the class. Additionally, the arguments he makes regarding yoga slowing your metabolism and potentially providing weight gain seem a little misguided. I totally agree that yoga can calm you and in turn slow your metabolism. However, depending on the type of class you are in, yoga can be an intense physical workout. So you are burning calories. If were to replace all of your cardio activity with yoga and continue to eat the same amount... then yes, you would probably put on weight. However, if a sedentary person added yoga to their regimen and continued to eat the same amount, I would speculate that the calories burned in that class alone would offset any slowing in the metabolism.

Either way, the book did provide some very good insight on yoga research. Coming from an engineering background, I really appreciated the scientific explanations for results I've experienced in yoga myself.

[Emily Shearer · Rating 4 out of 5]

SO much great information. More in-depth history of yoga and its real origins and developments than any other source - and that includes every book on the required reading list of a 200 hour Yoga Teacher Training. I am a Registered Yoga Teacher, and I believe this book should be included in every training's syllabus. The risks it highlights are not scare tactics, rather information anyone should have access to to be an informed participant in any practice or activity.

[Kenya Wright · Rating 1 out of 5]

Yeah. Not a fan. For me, it was a pretty negative view at times on a positive way of life. Not to say it was all garbage. Just that I found the author searching for a way to call bullshit on the practice of yoga.

[Murf Reeves · Rating 4 out of 5]

I found the Science of Yoga to be very informative as a historical reference to the development of yoga and all its practices as well as connecting with my own journey with different aspects if the book resonating in my current practice and leading me to my next step.

[Jamie · Rating 3 out of 5]

Thoroughly researched and reasonably well-written. Broad summarizes the science around yoga capably in the vein of Mary Roach. He approaches a subject which interests him and in which he is personally invested with objectivity and appropriate distance. He travels to locations of interest and interviews professionals in the field without giving the impression that the book was written as an excuse for a pilgrimage or to meet gurus (as with the documentary Enlighten Up). Broad's interpretations of what his research uncovers is mostly good, and provides an overall structure to the book that could have created more of a through-line if it had been teased out a little more in each section. As I've found with Mary Roach, he tends to overemphasize peripheral elements and under emphasize central tenets. I'm not sure if this is in the service of adding interest or because he is a visitor to the research; it didn't seem like he did it to serve any agenda. It's a pitfall for the best science writers, probably--overemphasizing peripheral findings of research, or oversimplifying for lay audiences to the point that the research seems to say something it doesn't.

I enjoyed it thoroughly, however. I recommend it as a good starting point for anyone interested in the "nerdy" side of yoga. General yoga enthusiasts will probably be bored, and those already deeply immersed in yoga research will find it too basic for their needs. The notes and bibliography will give me reading material for months to come!

[Karin · Rating 2 out of 5]

Het boek biedt wat de ondertitel belooft: een nuchtere kijk op yoga, en dat is een prettige benadering. Jammer genoeg verzandt het iets te vaak en te veel in een opsomming van onderzoeksresultaten en individuele ervaringen, maar het valt te prijzen dat de auteur een poging doet om alle diverse claims over de voordelen van yoga op waarde te schatten. Verder heb ik er echter niet heel veel uit gehaald, al vond ik de gedeelten over de ontstaansgeschiedenis en vervolgens verwestering (en vercommercialisering) van yoga wel erg interessant.

[Mehul · Rating 3 out of 5]

Informative overview of Yoga as a physical discipline, including history, relevant scientific studies. The book covers some poses along the way, but don't expect a scientific in-depth look at them and anatomy.

[Hayley · Rating 2 out of 5]

Science of yoga, wasn't really that interesting for science it was more like the bias of yoga and that so much more research needs done
Wouldn't really recommend