{review} debunking the science of yoga

William J. Broad offers up a detailed exploration of scientific inquiry combined with numerous anecdotes about the Western practice of yoga in The Science of Yoga: The Risks and the Rewards.

Broad, a science journalist and senior writer at The New York Times, said that he took on the project because he felt the literature surrounding yoga was insufficient. He wanted to cut through the confusion of modern yoga and figure out through research "what's real and what's not, what helps and what hurts, and why."

The book is divided into a number of helpful chapters -- covering themes like health, fit perfection, moods, risk of injury, healing, sex and muse -- as well as illustrations, key "characters" and styles of yoga, and a basic chronology. These last couple of sections are great, whether you're brand new to yoga or not, because it's easy to get confused with all the names and terminology floating around; likewise, I often hear questions about where yoga "comes from" and such, so the timeline specifically provides a bit of history.

health, fit perfection and moods

Broad sorts through Indian texts and stories regarding the "miracle" of yoga in comparison to today's varied claims that yoga serves as a ideal type of activity from a sports lens. He dives into the details of many studies white papers, which all seem to claim that yoga does seem to improve balance, reduce fatigue, decrease anxiety, cut stress, lift moods, improve sleep, reduce pain, lower cholesterol and generally raise one's quality of life (73). But every scientist he came across noted that all of these wins also have limitations in terms of physical fitness; yoga is not necessarily "a path to physical superiority," even though it is frequently asserted as such.

Similarly, the "Moods" chapter identifies story after story about how yoga has improved the emotional well-being of people through the power of focused intention on breath, unwinding and presence. Broad takes a specific interest in the myth of how breathwork in yoga supposedly "get more oxygen" to your brain. He says,

Science over the decades has learned a lot about how yoga breathing affects a person’s mood and underlying metabolic state. Fast styles tend to excite and slow ones to calm.

And it has nothing to do with getting more or less oxygen into the practitioner’s body, contrary to innumerable yogis and gurus, video discs and yoga books, blogs and newsletters.

risk of injury and healing

Broad states that there are two extremes presented when it comes to asana, the physical postures of yoga: one, that yoga has always been presented as a safe, gentle, healing form of movement that renews -- despite its often contortionist, Instagram-worthy possibilities. And two, that some physicians have gone too far in lauding stories of injury as the common experience of a practitioner. Like anything else, yoga actually falls someplace in between, and Broad spends some time explaining how modern yoga has actually become more sensitive and responsive to the risk of injury in recent years. 

He also interviews a wide range of instructors who fall somewhere along this same gamut. Some claim that certain poses are unsafe for everyone, or unsafe based on physical structure and body alignment, or perfectly safe for everybody regardless of body type or past injuries. Broad notes a number of specific yoga postures known to be worrisome and controversial, such as headstand, full lotus, shoulder stand, side angle, triangle and plow pose -- and he spends some time breaking those poses down with concurrent studies that advocate for or against them. It's extremely educational, without bias. 

divine sex and muse

These two chapters are the shortest, and the former indicates the low number of scientific studies on how yoga relates to sexual pleasure. Broad mostly focuses on research around sexual misconduct and yoga instructors, though he notes that there's a popular commercial trend around the promise of yoga improving your sex life. He also expands on research being done by scientists on hormones, brain waves, skin conductivity and heavy breathing, and how all relate to elation, exhilaration, orgasm and a state of bliss known as samadhi. Broad ends the chapter discussing how old and modern accounts of kundalini, commonly known as a spiritual fire of sorts, are vague when it comes to any basis in physicality -- though personal accounts of reaching such spiritual heights are everywhere.

The muse section features stories and research related to links between yoga and creativity, yoga and finding a state of inner calm, and yoga as a means of inspiration. Broad doesn't point to any claim being correct, here; he just lays out everything he was able to find and asks the reader to consider it all, while noting that the scientific findings are modest at this point.

In the epilogue, Broad says that yoga is at a turning point: it is now more closely aligned with science, which may frustrate traditionalists, but the stakes for safety are high and the discipline hasn't reached its true potential. He writes,

Western science tends to view the body as a fixed thing with unchanging components and functions. But yoga starts from a different premise. It sees a lump of clay. The body in this view is awaiting the application of skilled hands.

He advocates for public funding of yoga research and concerned advocacy, and says in the same breath that getting those two things off the ground is unlikely. But he concludes:

As a society, we are learning that extended old age can mean extended pain and debilitation, with worn-out organs and crippling dementias turning the twilight years into tragedies. Yoga seems to hold out the promise of increasing not only our life spans but our health spans. It may be part of the answer to enhancing not just the quantity of life but its quality, to helping us remain healthy for a longer period of time, to making our last years more vital and productive. That promise seems like a wonderful topic for a serious program of research...

I treasure the scientific method . . . and the science of yoga may be demonstratively true, [but] yoga may see further. . . or maybe it’s all delusional nonsense.

The bottom line: transcendental bliss starts with the firing of neurons and neurotransmitters, with surges of hormones and brain waves.