Yoga vs. Stretching: The Research Evidence

photo credit: tokyosucks

If you’ve been paying attention to the news recently, you may have noticed a rash of conflicting headlines about yoga, stretching, and healing back pain.

“A Study Finally Proves Yoga Can Help Ease Back Pain,” reported a celebratory Well + Good NYC. But wait. Was the news really that good? “Yoga No Better Than Stretching for Bad Backs,“ scoffed a headline at the Telegraph.

The Huffington Post was admirably even-handed. “Yoga And Stretching Help Chronic Back Pain, Study Shows,” ran their just-the-facts-m’am headline. The Wall Street Journal, in contrast, didn’t waste the opportunity to take an anti-yoga potshot. “Yoga May Help Low Back Pain. Mental Effects? Not So Much,” their headline disparagingly blared (perhaps, I can’t help but speculate, reflecting some irritation over recent public displays of yoga (PDYs) in support of Occupy Wall Street?)

Although you wouldn’t know it from the headlines, all these reports (and many others) were based on the same study. Kinda confusing, no?

Research Findings vs. News Headlines

Curious about the real deal here, I tracked down the original report, “A Randomized Trial Comparing Yoga, Stretching, and a Self-Care Book for Chronic Low Back Pain,” recently released in the AMA’s Archives of Internal Medicine. After reading it, I came to several basic conclusions:

  • The first three headlines are reasonable ways of summarizing the research. The WSJ’s, however, is highly misleading.
  • There’s a huge difference between studying the physical and mental effects of yoga, and testing whether it’s a potential short-term intervention to help back pain. This distinction gets lost in the reporting, which confuses everything.
  • It’s important to be clear on the general strengths and limitations of this type of study when it comes to interpreting the results, and what they tell us about yoga.

This was an important study because it followed what’s known in research as the “gold standard” of a “randomized trial.” What does this mean? Simply that they took a group of people with the same problem (228 adults with chronic low back pain) and randomly sorted them into three groups, which received three different interventions:

  • 12 weekly 75-minute yoga classes,
  • 12 weekly 75-minute stretching classes, or
  • a back self-care manual to work with at home.

Each of the three groups was instructed to practice for 20 minutes at home on days with no classes. Then, the researchers assessed outcomes at 0, 6, 12, and 26 weeks and compared the results.

The yoga classes included asana, pranayama, body awareness cues, and guided deep relaxation. Instructors had at least 500 hours of Viniyoga training and five years teaching experience. The stretching classes included aerobics, strengthening exercises, and lots of stretching. They were taught by licensed physical therapists that had completed a two-hour training program and had previous teaching experience.

The main finding of the study was summarized as follows:

Yoga classes were more effective than a selfcare book, but not more effective than stretching classes, in improving function and reducing symptoms due to chronic low back pain, with benefits lasting at least several months.

So: the first three headlines are accurate. The study proves that yoga helps back pain. It also proves, however, that it’s “no better than stretching,” at least when it comes to a 12-week intervention – which, in all fairness, is precisely the sort of short-term timeframe that medical researchers are rightfully concerned with. They want to know what works quickly for the average person, and this study was a good way to test that out.

chemistry bottles with liquid insidephoto credit: zhouxuan12345678

“Mental Effects” Not Tested

The Wall Street Journal began its story about this study by stating that:

A study believed to be the largest of its kind suggests that the physical aspects of yoga are effective at relieving low back pain, but it didn’t find any evidence that yoga provided broader mental benefits.

Like the headline itself (“Yoga May Help Low Back Pain. Mental Effects? Not So Much”), this is completely misleading. Even worse is the headline that came up when I linked to this story on my Facebook Page, “Doubt Cast on Yoga’s Mental Benefits.” For goodness sakes: the study was not designed to test the “mental benefits” of yoga. It was purely and simply set up to see how a 12-week course of yoga compared with the same amount of stretching classes (or working from a manual at home) in terms of easing chronic back pain.

True, the researchers had hypothesized that yoga would have a bigger impact than stretching due to its “mental benefits.” And they found that this was not the case – which is an important finding. But they didn’t check to see if other mental benefits had occurred during that 12-week period. Had students experienced something important to them as a result of the yoga-specific body awareness cues, breath work, and guided meditation? We have no way of knowing, as the researchers didn’t ask.

Interestingly, however, they did check to see how much people liked the classes, and found quite a big different there. While 85% of the yoga students said that they’d “definitely recommend the class to others,” only 54% of the stretching students said that same. That, my friends, is a big difference! Plus, it should be noted that the stretching classes featured “substantially” more stretching than what’s “typically found in publically available classes” – in other words, they were a lot like yoga classes!

This means that the main difference between the yoga and stretching classes was the body awareness, breathing, and meditation. And those elements of the class made a 30% difference in terms of how much students liked it! Plus, I would hypothesize that if students really like a class, they will be more likely to stay with it – which will help their back problems more in the future! So . . . I would conclude that the study in fact provides plausible evidence that that the “mental” aspects of yoga do make a difference, even in a limited 12-week intervention. It’s just that the researchers weren’t asking the right questions to find out what they were.

Limitations and Opportunities

Finally, it’s important to be clear about what this type of study can do well – and what it can’t. It was well designed to answer the question of how different short-term, non-medical interventions work in terms of easing chronic back pain. It was not well designed at all, however, to answer the question of whether yoga confers any “mental benefits” that stretching doesn’t during this short period of time.

If you were interested in answering this question, it could be done to some extent by designing research instruments that try to capture the range of “mental benefits” that one might plausibly experience as a beginning yoga student whose motivation was healing back pain (not developing meditative awareness) and who had only experienced only three months worth of classes. Did they experience any new sense of calm? Deeper relaxation? Body awareness? Etc. A relevant questionnaire could be developed and administered.

As any more experienced yoga student knows, however, measuring the “mental benefits” of yoga is always going to be a much more tricky business that any set of 5-point rating scales could capture. Some individuals are open to working with their minds in yoga; others are not. Some practitioners will cue into the experience of body awareness, mental concentration, and deep relaxation immediately; others may practice for years before connecting to yoga in this way.

Chakra Displeasurephoto credit: Claire L. Evans

Finally, anyone who has studied yoga in-depth knows that the capacities of mind it can develop go far beyond the current boundaries of Western science.  Studying the “mental benefits” of yoga in ways that are appropriate to the fuller capacities of the practice would require radically changing the mindset and protocols of conventional research.

Taking the methods that we have and plugging yoga into them is fine for telling us certain things, like whether three months of yoga classes can help back pain (yes) and how that compares to stretching (the same). It can’t, however, tell us anything about the “mental benefits” of yoga. And it’s unnecessarily confusing and misleading to suggest that it can.

Do you think that scientists should study the mental benefits of yoga? What would a well-designed study look like?

Do you think that this study did a good job at assessing whether yoga helps chronic back pain? Is there anything that you would change to try to generate more valuable results?

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- who has written 8 posts on Yoga Modern.

Carol is a Contributing Editor to Yoga Modern. A Certified Forrest Yoga Teacher, she teaches yoga to incarcerated women at the Cook County Women’s Detention Facility with the non-profit group, Yoga for Recovery. Author of Race and the Making of American Liberalism (Oxford University Press, 2005), she’s currently finishing a new book entitled 21st Century Yoga: Paradoxes of Contemporary Practice. Carol holds a Ph.D. in Political Science from the University of Chicago and taught American Politics at Macalester College in St. Paul, Minnesota. Since leaving academia to be with her husband in Chicago and start a family, she’s worked as a research consultant to nonprofit organizations, specializing in issues affecting low-income children and families. In addition to Yoga Modern, her online activities include blogging at Think Body Electric and Elephant Journal, maintaining a Facebook Page dedicated to news and discussion about yoga and meditation, and mixing it up on Twitter. Carol lives in Chicago with her husband, two sons, and two krazy catz.

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