For many yoga devotees, the name B.K.S. Iyengar is synonymous with the practice itself. Asking deeply practical questions like “How can you know God if you don’t know your big toe?” and injecting an innovative approach to physical poses—he pioneered the use of props such as blankets, straps, and blocks—Iyengar made yoga accessible to millions around the world. In this illuminating documentary, we see him teaching, lecturing, and effortlessly demonstrating the pretzel-like poses he’s known for. Interviews with family members and other teachers who embrace the mental discipline and spiritual focus that lie at the core of his approach provide context, and several people who have incorporated Iyengar’s transformative principles into other work—for example, a rehab program for recovering addicts—speak to the reach of this practice.