Use of Sport Supplements and Doping Substances by Athletes: Prevalence and Relationships.

: The use of sport supplements may represent a risk factor for the use of doping in sports. To explore this putative risk, the current study examined the frequency of sport supplement use and associations between the use of sport supplements and the use of doping substances and methods in athletes. : The participants ( = 345; 56% male, 22 ± 5 years, 18-43 years) completed measures of sport supplement use, sport supplement beliefs, doping likelihood, and doping use. Based on the Australian Institute of Sport's "Sports Supplement Framework", the participants were asked whether they used 23 sport supplements from four categories (sport foods, medical supplements, performance supplements, other). They were also asked whether they used six classes of doping substances and methods (alphabodies, stimulants, steroids, erythropoietin, growth hormone, blood doping). : Sport supplements were used by 96% of the athletes, whereas doping substances were used by 4% of the athletes. Moreover, athletes who used more sport supplements also used more doping substances. The use of sport supplements was related to the use of doping substances both directly and indirectly via sport supplement beliefs and doping likelihood. : Consumption of sport supplements is common, whereas doping is rare, and, moreover, the belief that sport supplements help optimize performance in competitive sport confers an increased risk for doping.