The Science of Yoga

earliest days of the English language and that its first definitions resonate with existential import. “Mood” was originally a synonym for “mind.” In Old English, the word mod meant “heart,” “spirit,” or “courage.”
    An intriguing question that investigators have yet to address is whether yoga can change an individual’s pattern of moods—in other words, a person’s core emotional outlook. Can the regular practice of Sun Salutations produce a sunny disposition? Does yoga bring about what might be considered characteristic states of affability?
    Many people have looked to their own experience on such matters and found that, overall, yoga lifts their emotional life. Significantly, the vast majority are women.
    The conventional wisdom is that episodes of major depression strike women twice as frequently as men. The drug evidence is stark. A survey found women nearly three times as likely as men to take antidepressants—with usage as high as one in every four or five women.
    If those characterizations are right, yoga should resonate strongly with women as a way of fighting the blues. I personally saw evidence of that attraction. In the early winter of 2010, I joined dozens of women (and a few guys) who had gathered to learn about using the discipline as a means of emotional uplift.
    “It really saved my life,” Amy Weintraub told us during her introductory talk. “I wouldn’t be here.” It was Friday night at Kripalu, the yoga center in the Berkshires of western Massachusetts. Weintraub, author of Yoga for Depression , was leading a weekend seminar on mood management.
    She came to hercalling after a life of crippling dejection and numbness. “I moved as through a fog,” she recalled in her book. “I lost keys, gloves, and once, even my car.” Antidepressants did little. Then she found yoga. The fog lifted. In a year, she was off drugs and soon became a yoga instructor. Her rebirth came with deep feelings of emotional strength.
    At Kripalu, for three days, Weintraub marshaled every available weapon in the yoga arsenal to teach us how to seize control.
    “You’ll be feeling lighter and brighter or your money back,” she said with a smile. Her methods were not particularly strenuous. But they all took aim with great precision at lifting the spirit. We relaxed. We visualized. We did balancing poses that forced us to shift our attention from mind chatter to the here and now. We laughed. We stretched. We made calming sounds. We did Breath of Joy—inhaling, bringing our arms slowly up to the sky, then exhaling with a breathy “Haaaa” while bringing our arms down rapidly. By the end of it, we glowed, lit from within.
    Weintraub understood the science and told our class about a number of studies and researchers. It turned out that she knew Khalsa and was working with him on one of his investigations—to compare the benefits of yoga with those of psychotherapy. She also had a book in the works: Yoga Skills for Therapists .
    All this may sound new and fresh. But it turns out that Harvard, Boston, and Massachusetts have long played host to individuals and institutions with abiding interests in yoga’s emotional sway. In fact, I suspect that is the core attraction of Kripalu, which has drawn waves of interest for decades and describes itself as the nation’s largest residential center for yoga and holistic health. The facility is located on hundreds of rural acres far from the usual pleasures and distractions of urban life.
    On the Friday that I signed in—with the leaves of the trees gone and the area dappled in white from a recent snowfall—Kripalu succeeded in registering nearly five hundred guests for its weekend classes. The vast majority were women.
    Thoreau characterized yogis as having no earthly care: “Free in this world as the birds in the air.” In 1849, he told a friend that he considered himself a practitioner—the first known instance of a Westerner making that claim. “I would fain practice the yoga faithfully,” Thoreau wrote. “To some extent, and at rare intervals, even I am a yogi.”
    At Harvard, his almamater, William James looked favorably on yoga as a means of mental regeneration. The famous psychologist, trained as a medical doctor, zeroed in on one of yoga’s most basic exercises—the simple but systematic relaxation of the muscles.
    The pose is called Savasana, from sava, the Sanskrit word for “dead body.” Today we call it the Corpse. It is the easiest