Somatotype and bioimpedance vector analysis: A new target zone for male athletes

Background: Bioelectrical impedance vector analysis (BIVA) is a body composition assessment method based on the interpretation of the raw bioimpedance parameters. While it was initially proposed in clinical settings, its use in the sports field has grown considerably. The aim of this study was: (i) to explore the role of somatotype on BIVA patterns and (ii) to propose a new target zone to improve BIVA analysis in ball games athletes. Methods: One hundred and sixty-four male volleyball, soccer, and rugby players (age 26.2 ± 4.4 yrs; body mass index (BMI) 25.4 ± 2.4 kg/m2) were included in this study. Somatotype and BIVA were measured from anthropometric and bioelectrical data, respectively. Results: Forty-six athletes were classified with an endomorphic mesomorphic somatotype, 26 showed a balanced mesomorphy, 55 were ectomorphic mesomorph, 10 resulted as mesomorph ectomorphs, 13 with a mesomorphic ectomorph somatotype, and in 14 athletes a balanced ectomorphy was assessed. The results of the Hotelling's T2 test showed significant differences in BIVA patterns for the endomorphic mesomorph group (p < 0.001) in comparison with all the other groups, while mesomorphic balanced athletes presented a more inclined vector compared to the athletes with a balanced ectomorphy (p < 0.003). In addition, the endomorphic mesomorph group showed a greater BMI (p < 0.001) with respect to the athletes grouped in the other somatotype categories. Discriminant analysis revealed two significant functions (p < 0.001). The first discriminant function primarily represented differences based on the bioelectrical standardized resistance parameter (R/H) measure, while the second function reflected differences based on the bioelectrical standardized reactance parameter (Xc/H). Conclusions: Athletes presenting a higher endomorphic component have a lower vector, whereas those with a larger mesomorphic component display higher vector inclinations on the R/Xc graph. We propose a new target zone to improve the interpretation of BIVA analysis in athletes engaged in team sports.