• In 1879, Scots-Canadian biologist George Romanes suggested a physiological defense for working outside one’s discipline. In his essay on “Recreation,” Romanes theorized that different activities use up nutrients and energy in different muscles and parts of the brain. According to Romanes, a historian practicing science and a scientist studying history find recreation in each other’s labors because they are pursuing a different kind of work than they normally would. This restores their energy, helping the scholar stay healthy and allowing them to continue to work in the future. Unlike Romanes, those calling for interdisciplinarity today do not typically focus on academics’ health. Instead, advocates for interdisciplinary pursuits argue that they produce new knowledge and help ideas to diffuse across disciplinary boundaries. However, in this paper I argue that the Victorian professionalization that led Romanes to classify working outside of disciplinary borders as a form of ‘recreation’ in the nineteenth century continues to shape the way many think of disciplinary and interdisciplinary study today.