Challenges the popular view that yoga is timeless and unchanging by examining the history of yoga, focusing on its emergence in modern India and its dramatically changing form and significance in the twentieth century. Alter argues that yoga's transformation into a popular activity idolized for its health value is based on modern ideas about science and medicine. He centers his analysis on an interpretation of the seminal work of Swami Kuvalayananda, one of the chief architects of the Yoga Renaissance in the early twentieth century. From this point of orientation Alter explores current interpretations of yoga and considers how practitioners of yogic medicine and fitness combine the ideas of biology, physiology, and anatomy with those of metaphysics, transcendence, and magical power.

Yoga has come to be an Icon of Indian culture and civilization and it is widely regarded as being timeless and unchanging. Based on extensive ethnographic research and an analysis of both ancient and modern texts, Yoga in modern India challenges this popular view by examining the history of Yoga, focusing on its emergence in modern India and its dramatically changing form and significance in the twentieth century. Joseph Alter argues that yoga's transformation into a popular activity idolized for its health value is based on modern ideas about science and medicine.