The Science of Yoga

It happened not only with respiratory physiology but psychology, cardiology, endocrinology, and neurology. The scientists often acted with rigor, going against the day’s tide.
    Intrigued, I traveled to India to learn more about these early investigators and eventually came to see them as a kind of intellectual vanguard. Their reports tended to predate the electronic archives of PubMed, making them all but invisible to modern researchers. But their findings turned out to be central to the field’s development.
    As I widened my research, I had the great good fortune to sit at the feet of Mel Robin, a veteran yoga teacher and star of yoga science. Mel had worked at Bell Telephone Laboratories (the birthplace of the transistor, the heart of computer chips) for nearly three decades before turning to an investigation of yoga. His labor of love produced two massive books totaling nearly two thousand pages. What Mel did uniquely was roam far beyond the literature of yoga to show how the general discoveries of modern science bear on the discipline. His example encouraged the kind of independent thinking I had begun at the University of Wisconsin.
    Over the years, the widening of my research brought me into contact not only with Mel but a wonderful variety of scientists, healers, yogis, medical doctors, mystics, federal officials, and other students of what science tells us about yoga. If science is the spine of this book, they are the flesh and blood.
    My focus is practical. In places, the book touches on topics of Eastern spirituality—meditation and mindfulness, liberation and enlightenment—but makes no effort to explore them. Rather, it zeroes in relentlessly on what science tells us about postural yoga. I mean no disrespect to the Hindu religion or spiritual traditions that embrace the big picture. But if this book succeeds, it does so because it limits itself to a poorly known body of reductionist findings. Even so, I should note that I view the scientific process as limited and unable to answer the most important questions in life, as does any true believer. The epilogue explores what may lie beyond.
    In the end, my examination revealed not only a wealth of findings but a remarkable lack ofknowledge among yogis, gurus, and practitioners about the reports and investigations. This is pure speculation. But I’d be surprised if the community knows a hundredth or even a thousandth of what scientists have learned over a century and a half.
    This book tells that story. In essence, it offers an impartial evaluation of an important social phenomenon that began to stir millennia ago. And if I may, it is the first to do so.
    I have structured this book to start with issues of common interest and to end with topics that are less familiar. That flow, it turns out, parallels the development of scientific interest over the decades. So the book has a loose chronological organization.
    The portrait of yoga that emerges is quite different in important respects from the usual claims. In some cases, the news is better.
    For instance, a number of teachers credit yoga with powers of sexual renewal. The science not only confirms that claim but shows how specific poses can act as aphrodisiacs that produce surges of sex hormones and brain waves indistinguishable from those of lovers. More generally, recent clinical studies give substance to the idea that yoga can improve the sex lives of men and women, documenting how new practitioners report not only enhanced feelings of pleasure and satisfaction but emotional closeness with partners.
    The health benefits also turn out to be considerable. While many gurus and how-to books praise yoga as a path to ultimate well-being, their descriptions are typically vague. Science nails the issue.
    For example, recent studies indicate that yoga releases natural substances in the brain that act as strong antidepressants, suggesting great promise for the enhancement of personal health. Globally, depression cripples more than one hundred million people. Every year, its hopelessness results in nearly a million suicides.
    Amy Weintraub, a major figure in this book, recounts how yoga saved her life by cutting through clouds of despondency.
    But if some findings uplift, others contradict the onslaught of bold claims and proffered cures.
    Take body weight—a topic of enormous sensitivity for anyone trying to look good. For decades, teachers of yoga have hailed the discipline as a great way to shed pounds. But