Bodybuilding, dietary supplements and hormones use: behaviour and determinant analysis in young bodybuilders

BACKGROUND: Among athletes, bodybuilders are more predisposed to the use of dietary supplements (DS) and hormones (H) to increase in adaptations to physical training and performance. The purpose of the study was to identify social, psychological, and organisational factors that are associated with the use of food supplements and hormones in young bodybuilders of the metropolitan area of Naples. METHODS: 107 athletes, practicing bodybuilding, were consecutively recruited in 30 gyms, randomly selected in the metropolitan area of Naples. Athletes were administered an anonymous questionnaire. The questionnaire consists of 5 sections (socio-demographic, frequency and reasons for bodybuilding, knowledge, attitudes and behaviours). Descriptive statistics were performed using T-test and Chi-square statistics. A score was created for knowledge, attitudes, behaviours. Multivariable logistic regression models were employed to assess association between each score and the use of DS and H. Statistical analyses were carried out using STATA 15. RESULTS: 81.31% of the subjects reported to use DS while 35.51% H. Females are less likely to practise bodybuilding frequently than males (OR 0.18 (95% CI 0.05–0.69), p = 0.01). Subjects who have attended high school or university have a lower probability of taking DS (OR 0.17 (95% CI 0.04–0.65), p = 0.01). H users also use supplements more frequently (OR 61.21 (95% CI 3.99–939.31), p < 0.001). Those who scored higher on knowledge scores are more likely to take DS (OR 1.53 (95% CI 1.11–2.12), p < 0.001). Attitudes are correlated with the use of DS; those who scored higher were less likely to use DS (OR 0.77 (95% CI 0.30–0.98), p = 0.03). People who use DS are 30 times more likely to use H at the same time (OR 30.25 (95% CI 2.51–365.24), p < 0.001). Subjects who have a higher score for knowledge and attitudes are less likely to use H (OR 0.68 (95% CI 0.54–0.87), p < 0.001, OR 0.75 (95% CI 0.62–0.90), p < 0.001). CONCLUSIONS: Prevalence of H and DS’ use, although lower than reported in the literature, is a worrying public health problem. Better knowledge can lead to an informed use. Gym instructors should be trained to provide accurate and scientifically sound information. Health professionals should combine their expertise to provide more comprehensive guidance to the exercisers. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13102-021-00378-x.