Physical fitness is inversely related with body mass index and body fat percentage in soccer players aged 16-18 years

Introduction: Adolescents are at increased risk for the development of obesity, while sport has been suggested as an effective means against adolescent obesity. The objectives of this study were to examine (a) the prevalence of overweight/obesity, (b) the relationship between body mass index and body fat percentage, and (c) the association between body mass index, body fat and physical fitness in soccer players aged 16-18 yr. Material and Methods: Members (n=109, aged 17.0±0.5 yr) of competitive soccer clubs were examined for physical and physiological characteristics. Results: Based on international body mass index cut-off points, 18.3% (n=20) of participants were classified as overweight. Body mass index was highly correlated with body fat percentage (r=0.70, p<0.001). Body fat percentage was in inverse relationship with aerobic power (r=-0.21, p=0.029), maximal anaerobic power (r=-0.20, p=0.044) and local muscular endurance (r=-0.39, p<0.001), while corresponding values of body mass index were non-significant (r=-0.05, p=0.614; r=0.03, p=0.771; r=-0.12, p=0.220, respectively). However, both body fat percentage and body mass index were inversely related with fatigue index of Wingate anaerobic test (r=-0.26, p=0.009; r=-0.29, p=0.003, respectively). Conclusions: The strong relationship between body mass index and body fat percentage suggest the further use of body mass index in adolescent soccer players. The findings confirmed previous observations on general population about the negative effect of overweight and fatness on physical fitness. The prevalence of overweight among participants was similar with what is observed in general population. Therefore, sport participation cannot guarantee physiological body mass and body composition, and it is necessary to prescribe exercise targeting body mass and fat control.