In this study, we sought to determine the prevalence of musculoskeletal injuries, perceived pain, and physical activity level among Brazilian practitioners of strength training (ST) and functional fitness (FF). Participants were 311 men and women who trained in 10 FF training centers and seven ST gyms. Each participant completed surveys of the prevalence of musculoskeletal injuries, their pain perception, and their physical activity level. A chi square test was used to analyze associations between groups and distributions of injuries. When any significant difference was observed, the difference score was analyzed through the adjusted residual values. Fisher's exact test was used to determined the associations between musculoskeletal injury prevalence and training modality (FF and ST) and between musculoskeletal injury prevalence and practice frequency (times/wk). To measure the magnitude of association between variables, the Phi coefficient was calculated for 2x2 associations and Cramer's V was used whenever the distributions were outside this standard. When the dependent variable presented a dichotomous characteristic, an Odds Ratio (OR) was calculated with a confidence interval of 95%. We found a higher musculoskeletal injury prevalence in the axial skeleton (n = 52; 83.88%) in FF practitioners and in the lower limbs of ST practitioners (n = 9; 52.96%). When the physical activity level cutoff point was set at 300 minutes per week, there was a significant relationship between physical activity and training modality (p = 0.005). There was also a significant association between pain perception and musculoskeletal injury (p < 0.001). Clinical follow-up was a protective factor to being injured (OR = 0.18; CI = 0.06-0.49), and, even after multivariate analysis this significant association was maintained (OR = 0.03; CI = 0.01 - 0.08). Thus, FF practitioners reported more musculoskeletal injuries than STs, and follow-up medical or physical therapy was a protective factor to these injuries. FF practitioners also had a higher level of weekly physical activity weekly than ST practitioners. Functional fitness practitioners may be at a higher risk of injuries than those who participate in traditional strength training.
Keywords: extreme conditioning; pain perception; physical exercise; physical training; sports science; training injuries.