ABSTRACT
The ability of a clean athlete to compete fairly relates to both the prevalence of doping and the effect size of doping regimes on performance. Effective anti-doping programmes should seek to reduce not only the prevalence but also the effectiveness of doping by limiting their available options to dope in terms of substances, doses, and timing of doping regimes. For the detection of blood doping in endurance sports such as cycling, the combination of the whereabouts system to locate athletes, the Athlete Biological Passport (ABP) to identify suspicious changes in biomarker values, and finally an arsenal of sensitive tests for erythropoiesis-stimulating agents (ESAs) offers a powerful toolset to identify doping athletes. The result for cycling has been several changes in behaviour that ultimately reduce the effectiveness of blood doping on performance, including reduced dosing, the use of less effective substances, and doping far from competition. The outcome is that the ability of clean athletes to win has greatly increased over the past decade. Investment in both basic research and anti-doping programmes must be a global effort in order to ensure a future where all clean athletes can compete with a fair chance to win across all sports.
