What is a Yoga Practice?

by Brad

A year or so ago I was talking with a colleague about a genomics study he was planning that was going to look at exercise and aging. Previously, he and his colleagues had shown that resistance exercise training had a significant effect on the genes that were transcribed in muscle tissue, and that the older people undergoing this training had gene transcription profiles that resembled much younger people. This time around they were planning a more nuanced study and would look at several exercise regimens, including yoga. I remembered asking him what type of yoga practice they planned to use, and was met with a slightly confused look. He wasn’t sure, but thought it was a “standard practice” involving some stretching and aerobic components. When I inquired further about whether it was Iyengar style or one of those high-energy aerobic practices (like Ashtanga Vinyasa), I realized that our discussion had reached a dead end. He had no idea what I was talking about.

Photo from Yoga: The Poetry of the Body by Yee and Zolotow

So when I ran across another article today on Yoga for Back Pain that was mentioned in the Science Times section of this weeks NY Times (see here), I decided to take a little closer look at what the actual practice was. I also looked back at the Ornish and Blackburn study I discussed a couple weeks ago (see here), as well as a few other studies I had run across. I was interested in seeing how well the practice was described and whether it made in sense.

I was surprised to find that the most high profile of these studies, the 2008 Ornish and Blackburn study (see here), had the least detail. What they described as yoga for stress management consisted of “gentle yoga-based stretching, breathing, meditation, imagery, and progressive relaxation techniques 60 min/day, 6 days/week”. In contrast, a study published this summer by Dr. Fishman on osteoporosis and yoga (see here ) was considerably more comprehensive, listing all 10 yoga poses by both Anglicized and Indian names, e.g., “Upward and Downward Dog poses (Adho Mukha Svanasana and Urdhva Mukha Svanasana),” as well providing an appendix of 13 figures illustrating each poses. It should be pointed out that the lead author of this study was extremely familiar with yoga, having practiced it in India for three before attending medical school.

Another group that was fairly thorough in their description was Sherman et al. which just appeared on-line a couple days ago (see here) in their study of chronic low back pain, where they describe a viniyoga practice consisting of 5-11 poses (with pictorial diagrams referenced from earlier 2005 paper by this same group (see here). Interestingly, these authors also provided the credential for the teachers as “instructors with at least 500 hours of viniyoga training, 5 years of teaching experience, and familiarity with the selected postures and who were briefed by our yoga consultant.” This paper also gave a defense of their yoga style (viniyoga), as “a therapeutically oriented style of yoga that emphasizes safety and is relatively easy to learn.” 

Iyengar-style yoga was used in another study examining stress and inflammation by Kiecolt-Glaser, et al (see here) because it ”emphasizes the use of props to help students achieve precise postures safely and comfortably according to their particular body types and need”. In this latter study, the 12 poses and timing of each were well described and was constant, and apparently selected “based on their purported relationship to immune function and/or restorative effects.”

Obviously not everyone is going to agree with what is a good or best yoga practice for stress, back pain, osteoporosis or whatever. But what is clear is that these studies need to provide a through description of the regimen (time, poses, teacher qualifications) and their overall rationale, so that if someone wanted to reproduce this study or compare it with another, they shouldn’t be in the dark as to what the yoga practice was. In the end, it’s you who is going to have to decide on what to believe, as the standards for comparing these practices, pose sequences, and yoga styles are confusing at best. Maybe Nina and Baxter can comment on this, as I’m not an expert.