In this article I discuss some of the findings of an on-going ethnographic study of two once-weekly circuit training classes held in one of the growing number of private health and fitness clubs. The article has four aims. First, to demonstrate and explore the active role of the body in a central practice of body modification/maintenance: i.e. circuit training. Second, to demonstrate that circuit training is a social structure which both shapes the activity of the agent and is shaped by (...) that (shaped) agent. I aim also to explore this structuration process. Third, to draw out a number of aspects of the sociality of body maintenance/modification. Training, I argue, is a form of symbolic interaction, localized within specific and durable social networks. The final aim of the article is to weave these various claims together into a coherent overall account of circuit training as a form of body modification. As an investigation of the embodied nature of practices of body maintenance and the active role of social agents in relation to these practices the article rejoins an important strand of sociological investigations of ‘the body’. At the same time, however, the article seeks to challenge those approaches, often rooted in Foucauldian analysis, which portray the body as ‘docile’ in relation to body maintenance. Foucauldian inspired studies often reify practices of modification as ‘technologies’ or ‘apparatuses’, ignoring the active role of embodied agents in these practices and eliding the difference between texts which prescribe ways of acting and the more messy and complex reality of those ways of acting. (shrink)