 Athletes have historically been willing to take legal and health risks to improve their performance , with some even stating their willingness to risk their lives , as exemplified by research by Mirkin , Goldman and Connor in researching attitudes to the so @-@ called Goldman dilemma . To prevent use of performance @-@ enhancing substances , athletes must submit to drug tests that are conducted both in and out of competition by anti @-@ doping officials or accredited medical staff . <unk> athletes are susceptible to higher testing upon return to competition . Athletes found to have taken substances on the World Anti @-@ Doping Agency 's banned list receive sanctions and may be banned from competition for a period of time that corresponds to the seriousness of the infraction . However , the use of substances not on the prohibited list may also result in sanctions if the substance is deemed similar to a banned substance in either composition or effect . Athletes may also be sanctioned for missing tests , seeking to avoid testing or <unk> with results , refusing to submit to testing , through circumstantial evidence , or confession of use . 
