The Science of Yoga

You may think that yoga and science make strange bedfellows, but that’s beginning to change. As yoga’s popularity has exploded in recent years, the scientific establishment has finally begun to examine the evidence supporting the many claims about yoga’s benefits.

In his new book, The Science of Yoga, William J. Broad, who, as a leading science journalist for The New York Times and a long-time yogi, seems uniquely suited to this task, begins to elucidate the mounting evidence both in support of and against some of yoga’s oft-quoted maxims.

Over the course of seven chapters, covering topics like physical fitness, mood, injury and sex, Broad aptly interprets new data, unearths some previously unrecognized studies and clears up a few physiological misunderstandings along the way. Each chapter looks at the message commonly dispensed by the yoga community and compares it to reliable research on the subject.

Broad’s chapter on yoga and physical fitness falls squarely under the “myth busting” banner. Of particular interest is his evaluation of a number of studies that have examined whether yoga can significantly raise participants’ cardiovascular fitness level. In summarizing the research on the subject, Broad takes exception to a 2001 University of California at Davis study that stands out as the lone modern study suggesting that yoga could offer cardiovascular benefits. The study’s results were heralded in a 2002 article in Yoga Journal, entitled “Is Yoga Enough to Keep You Fit?” Broad also looks at the effects the dissemination of this article may have had, which brings us to the biggest surprise (for me, at least) in The Science of Yoga: I’m in it.

It seems that in 2008, I wrote a blog post entitled “Does Yoga Keep You Fit?,” in which I suggested that my readers might be interested in reading the above-mentioned Yoga Journal article. The post reads:

“Is Yoga Enough to Keep You Fit?” asks the headline of this in-depth article on yogajournal.com. Though the health benefits of yoga have yet to be exhaustively studied, the early evidence suggests that those with a regular (more than twice a week) yoga practice need not supplement their fitness regimes with other types of exercise in order to stay very physically fit. Which is good news for folks like me who really don’t like most types of exercise (except yoga, obviously).

[I’ve taken the liberty of correcting several typos that appeared in the original post.]

In referring to my blog post, Broad wrote:

Even The New York Times lost its bearings. One of its companies, About.com, addressed a frequent question of readers, “Does Yoga Keep You Fit?” Yes, came the unequivocal answer. Ann Pizer, the website’s “Yoga Guide,” said that recent science had revealed that students doing yoga more than twice a week “need not supplement their fitness regimes with other types of exercise in order to stay very physically fit.” She cited the original Yoga Journal article, the one that had turned the middling Davis study into a publicist’s dream come true.

Let me acknowledge here that in 2008, I didn’t know anything about the studies that Broad considers to have more reliably concluded that yoga, in fact, does not meet the criteria for basic aerobic fitness. (Indeed, the definitive review article he cites wasn’t published until 2010.) I also have no problem accepting his interpretation of the data. I am not a scientist; I am a yoga writer.

However, I do take exception to his mischaracterization of my blog post as an answer to a reader’s question, as well as the use of the word “unequivocal.” In point of fact, I went out of my way to equivocate, saying that the results were preliminary. I contacted Broad in the hopes that after a second look at the original source of his quote he would agree that his enthusiasm for my enthusiasm was overstated.

Unfortunately, this was not the case.

Suddenly, I found it difficult to concentrate on the remainder of Broad’s book.

Eventually, I regained my equanimity (thanks, yoga!) and soldiered on. If I led you to believe that yoga could be good workout back in 2008, please accept my apology. In recompense, let me be the first to tell you that Broad does find, scientifically, that yoga has other redeeming values, such as improving mood, elevating testosterone and fostering creativity.

Other myths that fall to the chopping block include that yoga boosts your metabolism (it has the opposite effect) and that fast breathing increases your oxygen intake (it does not). Despite having found myself on the short end of Broad’s myth-busting stick, these sorts of interpretations of scientific data prove to be the book’s strong suit, offering the most edifying information. I even wish he had gone further in this regard, tackling some other commonly heard yoga-speak.

But maybe because my own wound still smarts, I got no pleasure from Broad’s naming names and taking individual teachers to task for their past errors. It’s as if he doesn’t believe in the inherent interest of his own scientific material. The serious nature of the book as a whole is undermined by the journalistic urge to heighten the story by pitting the good guys against the bad guys, and creating drama where none is required.

A prime example of this tendency is Broad’s chapter on yoga injuries, which was excerpted in The New York Times Magazine on Jan. 8, 2012 and created quite a buzz in yoga circles and beyond, even bringing stories of the dangers of yoga to several national nightly news programs.

Here the myth being addressed is that yoga is a completely safe practice. But does anyone really think that? While the information proffered on the rise of yoga injuries is valid and important, the sensationalist tone of the article brought out the mama bear in slews of yoga teachers and students who took to the Internet to defend the practice that they love and believe brings benefits that outweigh the risks. Even Broad himself admits as much in his epilogue, in which he argues that yoga’s future lies in its increased incorporation into mainstream medicine:

[Yoga] can turn our bodies into customized pharmaceutical plants that churn out tailored hormones and nerve impulses that heal, cure, raise moods, lower cholesterol, induce sleep, and do a million other things. Moreover, yoga can do it at an extremely low cost with little or no risk of side effects.

Except stroke and paralysis, of course. Thanks for the roller coaster ride. Who knew science could be such a thrill?

Disclosure: A review copy was provided by the publisher. For more information, please see our Ethics Policy.