This book offers a scientific approach to understanding the practice of hatha yoga. Through four-color, three-dimensional illustrations of major muscles, tendons, and ligaments, Ray Long describes the practice and benefits of hatha yoga. Specific anatomical and physiological descriptions highlight the agonist, antagonist, and synergist muscles that come into play with each pose. Volume I of the series describes the key muscles of hatha yoga and how they are utilized. From beginners to experts, this book will become a constant companion.