THE SCIENCE OF YOGA: The Myths and the Rewards. By William J. Broad. Simon & Schuster. 336 pages. $26.95.

There's a lot of mysticism surrounding yoga. Yoga instructors, or yogis and yoginis as some prefer to be called, tout that they can teach the many health benefits of the ancient practice. But how many of them are snake oil salesmen and how many are the real deal?

Even those who occasionally dabble in yoga may appreciate William J. Broad's approach to the subject. A yoga practitioner himself, he gives an insider's perspective, but he also takes a scientifically objective look and debunks many of the myths surrounding the practice and its practitioners.

Anyone who has ever taken a yoga class or followed along at home via a DVD has heard the many claims of the health benefits of yoga: It reduces stress, improves balance, stimulates weight loss, increases flexibility and more. But is any of that true?

Broad tackles each of the popular claims yogis make with intense scrutiny. His research is thorough and carefully noted. Through his research, he is able to confirm several claims and even explain why they're valid.

Despite some very technical subject matter, Broad presents it in a way that is easy to understand and anything but dry. And his appendices provide a wonderful collection of other resources for readers who want to delve deeper into the subject.

Broad's book also takes an interesting look at yoga's hum- ble beginnings as a sort of traveling side show in India to an immensely commercialized industry that continues to grow with yoga studios cropping up in cities all over the world selling not only lessons, but specialized clothing, books and equipment to supplement the practice.

“The Science of Yoga” is a great read for those who've been practicing yoga for ages, those who are just getting started and those who have no idea if their dog is facing downward.