Yoga Body : the Origins of Modern Posture Practice is a 2010 book on modern yoga by Mark Singleton. It is based on his PhD thesis, and argues that modern yoga is, in large part, a radical break from hatha yoga tradition, with different goals, and an unprecedented emphasis on asanas, many of them acquired in the 20th century. By the 19th century, asanas and their ascetic practitioners were despised, and the yoga that Vivekananda brought to the West in the 1890s was asana-free. Yet, from the 1920s, an asana-based yoga emerged, with an emphasis on its health benefits, and flowing sequences (vinyasas) adapted from the gymnastics of the physical culture movement. This was encouraged by Indian nationalism, with the desire to present an image of health and strength.