Fat-free mass and bone mineral content positively affect peak torque production in Brazilian soccer players

Abstract

BACKGROUND: Few studies thus far have investigated the relationship between body composition (in particular, bone components) and isokinetic strength performance. OBJECTIVE: To determine the relationship between bone mineral content (BMC), bone mineral density (BMD), and fat-free mass (FFM) with isokinetic strength performance variables in professional soccer players. METHODS: We recruited 20 elite male soccer players from the Brazilian league's first division teams. Participants underwent a concentric isokinetic evaluation of knee flexor and extensor muscles. Dual-energy X-ray absorptiometry (DXA) was used to determine body composition. The relationships between variables were analyzed using Pearson's product-moment correlation coefficient. RESULTS: Body composition variables were correlated with the strength output of knee flexor and extensor muscles in both lower limbs. FFM and BMC explained at least 50% of the variation in peak knee flexion and extension torque while BMD did not have the same effect. CONCLUSIONS: The relationships reported in this study indicate that the use of isokinetics and DXA in soccer players should be further investigated both for measuring athletic performance and for relevant clinical assessment.