The Science of Yoga

practitioners to a control group of eleven individuals who did no yoga but instead read magazines and popular fiction for an hour.
    The results, published in 2007, fairly glowed. The scientists found that the brains of yoga practitioners showed an average GABA rise of 27 percent. By contrast, the comparison group experienced no change whatsoever. Moreover, the yoga practitioners with the most experience or who practiced the most during the week tended to have real GABA surges. For instance, the practitioner who had done yoga for a decade experienced a GABA rise of 47 percent. One participant who practiced yoga five times a week had an increase of 80 percent, the levels of the neurotransmitter almost doubling.
    The scientists concluded that yoga showed much promise for treating anxiety and depression. Perry F. Renshaw, a senior author of the study and director of brain imaging at the McLean Hospital, noted with understatement that any proven therapy that is cheap, widely available, and shows no side effects has “clear public health advantages.”
    Encouraged, the team embarked on a new study. This time the scientists looked at nineteen subjects and a control group of fifteen people who walked for exercise, which was seen as having the same metabolic expenditure as yoga. The main subjects had no significant yoga experience. They learned the Iyengar style from scratch and practiced it for three months.
    The findings were published in 2010. They showed that even beginning yogis experienced major rises in the neurotransmitter along with improved moods and lessened anxiety. The average GABA rise was less than in the previous study—13 percent versus 27 percent, or about half as much. Still, the new yogis did better than the walkers. And, judging from the evidence, they felt much better about themselves.
    Significantly, one of the eleven coauthors of the study was Liz Owen, an Iyengar teacher who ran classes in the Boston suburbs of Cambridge and Arlington. Owen hadno doctoral or medical degrees but knew a lot about using yoga to lift moods. “Relax your body,” her website advised. “Nourish your soul.”
    During this same period, Khalsa worked hard on studies meant to see if mood adjustment could have demonstrable benefits for diverse careers and life stages. One centered on musicians. Khalsa did his investigation with teachers from Kripalu and focused the research on a renowned establishment just down the road from the Berkshires yoga center—Tanglewood, the summer home of the Boston Symphony Orchestra and its academy of advanced study for young musicians. The goal was to see if doing yoga could help the beginners overcome stage fright in general and, more specifically, perform better for the demanding audiences that came to Tanglewood for summer concerts.
    In 2005, Khalsa and Stephen Cope from Kripalu recruited ten volunteers from Tanglewood’s prestigious fellows program. The five men and five women were aged twenty-one to thirty, the average just over twenty-five. They included singers, as well as those who played the violin and viola, horn and cello. For two months, the ten volunteers underwent Kripalu training. The options included morning and afternoon sessions seven days a week, a weekly evening session, an early-morning meditation session, and vegetarian meals at Kripalu. The investigation also included ten fellows recruited as controls who had no yoga training.
    The results, though not earthshaking, were encouraging, as Khalsa and Cope reported in their 2006 paper.
    The study had assessed performance anxiety that the musicians felt in practice sessions, group settings, and solos. The yogis showed no difference from the control group in practice and group settings but did demonstrate a striking drop in performance anxiety during solos. That made sense, Khalsa and Cope noted. Research showed that such nervousness was low during practice, moderate in group settings, and high in solo performances. So the mood effects, they reasoned, would show up more during solos.
    During my visit with Khalsa, we sat in his Harvard office and pored over the Tanglewood results on his computer. A yoga mat was rolled up under his desk. “There’s no question the kids loved it,” he said. “The control group had hardly any change. But look at the yoga groups. Yoga brings you into themoment. It brings a feeling of joy or energy with activity, a kind of mindfulness.”
    The results were so positive, Khalsa added, that