Differences between the sexes in athletes’ body composition and lower limb bioimpedance values

BACKGROUND: The differences between the sexes in body composition are well established, although sports activity at an elite level seems to reduce them. The aim of this study is a comparison of the sexes in terms of athletes’ body composition with a three-compartment model and a localized bioimpedance analysis in elite soccer players. METHODS: 18 female and 18 male elite soccer players of the same age were matched (female=26.2±2.4, male 26.9±2.5; p=0.87). An assessment of body composition was performed through the integration of anthropometrics parameters, skinfold thickness and bioimpedance data. The evaluations were carried out in the morning on a group of athletes who were in a rested condition, having not exercised in the previous 12 hours and having fasted for breakfast. RESULTS: A body composition assessment shows higher values in females for hip circumference/height (female: 0.55±0.03, male: 0.52±0.02; p<0.01) and fat mass index (female: 3.7±0.7 kg/m2, male: 2.4±0.4 kg/m2; p<0.001), while there is no difference between the genders in the extra cellular mass index (female: 7.1±1.2 kg/m2, male: 7.6±0.4 kg/m2; p=0.11). A localized bioimpedance analysis describes well-defined differences in the thighs, while in the calves these differences are reversed for the reactance values. CONCLUSION: Sports activity seems to slightly reduce differences in the whole body. The different adaption at the same physical effort appears to be mainly related to cellular mass. This study shows for the first time localized bioimpedance values in female athletes.