Psychosocial factors and performance enhancing substances in gym users: a systematic review

The use of performance-enhancing substances (PES) occurs among gym/fitness center users. This systematic review aimed to analyze studies describing prevalence, attitudes, beliefs, and knowledge, as conceptualized in the Theory of Planned Behavior (TPB), influenced by the use of PES by this population. Twenty-six articles were identified from a systematic approach following the PRISMA statement via electronic databases (SPORTDiscusTM, PubMed, Scopus, Web of Science, B-On and Psychology and Behavioral Science Collection) and hand-searching bibliographies of reference lists. Only peer-reviewed primary research published in English, Portuguese and Spanish (1997-2016), focusing on gym/fitness center users and providing information on psychosocial factors (e.g., attitudes, beliefs, intention, social influence/ peer pressure) towards using PES, were included. It was concluded that the most prevalent substance used was anabolic-androgenic steroids (AAS). Attitudes of male bodybuilders using AAS as the prevalent drug are mainly related to aesthetic issues. Important influences come from groups (e.g., friends, training colleagues) and instructors. Although some AAS users indicated a general lack of knowledge of the potentially harmful effects of these drugs, others were aware of the side effects. The TPB illustrated a relationship between psychosocial factors influencing gym users to use PES.