Health-Related Quality of Life and Dietary Supplement Use in Physically Active People and Athletes: A Cross-Sectional Study.

The use of dietary supplements is widespread among athletes and physically active individuals, yet their impact on health-related quality of life (HRQoL) remains insufficiently understood. This study investigated the associations between supplement use, physical activity patterns, and HRQoL in a heterogeneous sample of 537 adults engaged in sports at amateur, professional, or recreational levels. Participants completed an online survey assessing demographics, supplement use, physical activity habits, and quality of life using the SF-36 questionnaire. Statistical analyses included chi-square tests and independent-samples t-tests to explore relationships between supplement use, body mass index (BMI), motivational variables, and HRQoL outcomes. Results indicated that 46.7% of participants reported consuming at least one supplement or substance, with an average of 1.91 products. The primary motivations included performance enhancement (30.7%) and combined performance and aesthetic goals (12.1%). A significant association emerged between supplement use and the consistency of physical activity over time, as well as the individual's motivation for engaging in exercise. Participants who maintained stable activity levels and those driven by performance or competitive motives were more likely to use supplements. In contrast, individuals exercising primarily for physical and psychological health were less likely to report supplement use. When comparing HRQoL scores, supplement users showed significantly lower levels of impairment due to emotional issues (RE), social functioning (SF), and bodily pain (BP). Among these variables, only Bodily Pain presented a small effect size, suggesting a meaningful difference between users and non-users. These findings highlight that while supplements are commonly used in athletic contexts, their association with improved quality of life is limited, and may even reflect attempts to manage physical discomfort. Further research is needed to clarify the directionality of these relationships and inform safe and evidence-based consumption.