Parkour is both a leisure practice and a method of navigating the objects and spaces of urban environments. Leisure practices are increasingly being acknowledged as contested political arenas and being theorised as resistance. Constraints have traditionally been characterised as impeding participation in a leisure practice. Recent research has, however, suggested a more situational understanding that seeks to account for the experience of leisure constraints and their negotiation. Issues of power and resistance must therefore be included within discussions of the organisation of, and access to, leisure settings and the complex processes through which individuals negotiate constraints. This paper draws upon original empirical research to explore leisure constraints within the context of post-structural theorisations of power, resistance, and the organisation of public space. Multi-method qualitative research was conducted with an international sample of participants and texts comprising semi-structured interviews and textual and discursive analysis of media articles and Website material. Key findings relate to the spatial-cognitive processes through which participants reinterpret material-spatial restrictions upon public behaviour to facilitate unscripted leisure practice and creative play. A significant conclusion is reached, that the spontaneous fun and creativity characteristic of Parkour is not achieved by the removal of constraint, but by the reinterpretation and utilisation of constraints -- by empowering the individual to wrest (admittedly partial and momentary) control of the power relations embedded within public urban spaces. ABSTRACT FROM AUTHOR