Title : Between performance and influence: How athletes perceive and use nutritional supplements

Nutritional supplement use has become widespread among athletes at all levels, driven by intensive marketing and promises of performance enhancement. This study, conducted within the framework of the IRIS project (“Improving athletes' risk appraisal and informed decision-making towards nutritional supplement use in recreational and competitive sport”), funded by the European Union through the ERASMUS+ Sport Programme, aims to examine consumption patterns, risk awareness, and regulatory challenges across six European countries. A mixed-methods design was employed, combining quantitative data from a survey of 468 athletes with qualitative insights from interviews with 22 competitors. The analysis explored differences in supplement use by country, gender, and awareness of potential risks, including contamination and misleading claims. Results revealed notable cross-national variation: over 60% of athletes in Finland and Portugal reported regular supplement use, compared to 45% in Greece. Gender differences were also observed, with male athletes demonstrating a 23% higher prevalence of use. Despite the high rates of consumption, awareness of associated risks was inconsistent. Only 28% of participants reported routinely verifying supplement quality, while 73% indicated exposure to exaggerated or misleading marketing claims. Regulatory awareness was limited, with just 12% of athletes able to identify relevant authorities, and 68% of national markets lacking standardized contamination testing procedures. These findings highlight significant gaps in both consumer knowledge and regulatory frameworks. The study underscores the need for strengthened policies, including mandatory quality testing, standardized risk communication, and clearer labeling practices. Additionally, targeted educational initiatives are recommended to improve athletes’ ability to make informed decisions. In conclusion, coordinated efforts among regulatory bodies, sports organizations, and public health stakeholders are essential to enhance athlete protection, reduce health risks, and preserve the integrity of sport.

Dr. Ana Sofia Tavares is a Full Professor at the Department of Diagnostic, Therapeutic and Public Health Sciences at the Lisbon School of Health, Polytechnic University of Lisbon, and an integrated member of the Health and Technology Research Center. She teaches in the BSc in Biomedical Laboratory Sciences and the MSc in Clinical Laboratory Technologies, which she currently directs. Her research focuses on Clinical Chemistry, Epidemiology, doping, and health-related behaviors, particularly the motivations underlying the use of performance-enhancing substances. She participates in national and international funded projects, has authored multiple publications, and is a member of the Human Enhancement Drugs Network.