<p>A central practice of both premodern and modern yoga, pr???y?ma ("breath control") is practised in yoga classes worldwide. Like the notion of pr??a ("breath", "vitality"), pr???y?ma has a longstanding history in South Asia, constituting the fourth limb of Patanjali's yoga. Since roughly 1850, pr??a and pr???y?ma have been reinterpreted in light of the ideas of Hindu reform movements, nineteenth-century occultism, science, biomedicine, and tran...