In this article Peter Charlish addresses the controversial issue of the use of performance enhancing drugs in sport. He looks at the legal basis for regulation via the World Anti-Doping Code and the nature of a sports participant's relationship with their governing body and the anti-doping organisations. He explains in the context of proportionality, the measures designed to combat doping in sport; the importance to the Code of the central principle of strict liability. Also, he highlights the use of non-analytical positives as a further method of detection of doping violations, whilst taking consideration of the impact of these measures on the human rights of participants.