Evaluation of Body Composition Changes by Bioelectrical Impedance Vector Analysis in Volleyball Athletes Following Mediterranean Diet Recommendations during Italian Championship: A Pilot Study

In a volleyball team, an optimal body composition might be reachable by monitoring both training plan and nutritional habits to obtain success in competitions. The Mediterranean Diet (MD) may represent a good choice to cover the nutritional needs of those practicing competitive sports. The aim of this study was to monitor body composition changes through bioelectrical impedance vector analysis (BIVA) during pre-season training sessions (P), the championship (C), and the play-off period, in volleyball players following MD recommendations. Our data showed that athletes maintained an optimal MD adherence over the study period. In the total population, we observed an upward and leftward shift of the vector on the resistance (Rz)/reactance (Xc) graph within the specific tolerance ellipses for the volleyball players. Using Hotelling's T-2 test, we found significant changes in BIVA parameters from P to C of the entire team, due to reduction in Rz/height (H) and increase in Xc/H, along with an increase in phase angle, body cell mass index, and skeletal muscle mass. Our findings support BIVA as a useful tool to monitor body adaptations of athletes and the MD as an optimal dietary pattern in sport setting to allow good performance in athletes.