As recently as the 1970s, yoga was still seen as an exotic eccentricity in many parts of the United States. Since then it has become a pervasive and popular exercise regimen if nothing elsea means of maintaining physical health even for those who disconnect it from its spiritual dimension. Stefanie Syman’s readable and solidly researched account traces yoga’s arrival in America to Emerson, Thoreau and the Transcendentalists of the 19th century. Its growth spread from the efforts of several Indian masters who understood how to trim ancient theology to modern needs and desires. By the ’70s many teachers found there was much money in divorcing yoga entirely from its religious roots, claiming that the physical exercises were sufficient to transform the practitioner into a healthier person.