Accessible, enjoyable book explores the history of yoga

Two thousand years ago the Hindu religion in India, already suffused with cult-like tendencies, freighted with social dogmas, and aflutter with mystical, otherworldly urges, met up with the Gypsy carnival and its tradition of nomadism, charlatanism and showmanship.

The result was the wandering yogi who, showing up in tiny villages here and there along the Gangetic plain, wowed the assembled masses with feats of legerdemain, acrobatics and magic.

What poor farmer wouldn't love the spectacle of a wandering mendicant who could tie himself in knots, charm snakes, disappear for hours in a pit without air (and emerge alive and smiling) and stop his own heartbeat? And of course, there was always the engaging prospect of sexual high-jinks and the yogi promise of high performance in the bedroom (producing boy babies), that gave Tantric yoga its special appeal.

For the yogi it was a living.

William J. Broad, a senior writer at the New York Times and award-winning science journalist, takes on these historical aspects of yoga, as well as yoga's modern guises in the popularly accessible, credibly researched, and breezily enjoyable "The Science of Yoga." Reading "The Science of Yoga" is like taking a carefree open-air automobile ride through yoga's fascinating past and its incredibly diverse present, a ride during which the reader can understand yoga's benefits for physical health, emotional fitness, balance, brain chemistry, peace of mind and mindfulness.

Naturally, there are some dangers. Latterly, charlatans and hucksters have emerged, selling dangerous poses and extreme workouts disguised as "styles" which emphasize sweating and over-work. And some yoga poses represent a threat, particularly to the neck and spine. But these are easily avoided, according to Broad.

Modern yoga has come a long way since 1837, when a maharaja in Punjab learned that a yogi had approached his court to propose a live burial as a demonstration of spiritual power. The holy man was interred in a small building. The yogi, wearing white and covered with lotus flowers, was placed inside a small box, which was buried in a shallow pit. A mud wall sealed off the box from the outside world. The interment lasted 40 days and nights, a period that from Biblical times has stood for the completeness of cycles. At the end of 40 days, the yogi - cold, stiff and apparently dead, opened his eyes and smiled.

Since that time yoga has undergone a revolution in form and content. A dozen or more styles have emerged incorporating deep breathing, yoga poses, chants, meditation and "props" like heated rooms, music, diet and other exercise routines. Over time, Hatha has been the most popular style with its varied poses and breathing. These days, entrepreneurs copyright their styles and fight about it in court with other entrepreneurs, a style known as litigation.

Broad guides the reader through the complex maze of these styles, sorting useful from faddish, dangerous from benign. Moreover, "The Science of Yoga" includes a useful index and bibliography, as well as a large number of well-drawn illustrations of yoga poses.

In general, science has pronounced yoga beneficial, even though the studies currently available are sometimes less than rigorous. Broad's book shows how yoga has been shown to decrease blood pressure, increase flexibility and balance, drop blood sugar levels, reduce back pain and increase overall muscular strength.