Sport supplement use predicts doping attitudes and likelihood via sport supplement beliefs.

The aim of this study was to examine: 1) whether sport supplement use is related to doping and 2) whether sport supplement beliefs mediated this relationship. In Study 1, athletes (N = 598), completed measures of sport supplement use, sport supplement beliefs, and doping attitudes. In Study 2, athletes (N = 475) completed measures of sport supplement use, sport supplement beliefs, and doping likelihood. In both studies, sport supplement use predicted doping outcomes indirectly via sport supplement beliefs. Our findings provide novel evidence to suggest that sport supplement users, who strongly believe that sport supplements are effective, are more likely to dope. For anti-doping organisations wishing to prevent doping, targeting an athlete's beliefs about sport supplements may improve the effectiveness of anti-doping prevention programmes.