Classical and specific bioelectrical impedance vector analysis values of children and adolescent athletes according to maturational status: a cross-sectional study.

OBJECTIVE: The aim of this study was to analyze classic (BIVAc) and specific (BIVAsp) bioelectrical impedance vector analysis values of children and adolescent athletes according to their maturational status. METHODS: A total of 78 subjects (36 male and 42 female), classified as prepubertal and pubertal, participated in the study. Bioelectrical parameters such as resistance (R), reactance (Xc), and impedance (Z) were measured using a tetrapolar bioelectrical impedance analysis (BIA) device (Sanny® BIA1011AF, 50 kHz, 800 μA) and subsequently normalized by height (BIVAc) and by body circumferences and height (BIVAsp). Five adjustment models were developed using analysis of covariance: raw; sex; sex and age; sex, age, and training experience; and sex, age, training experience, and weekly training volume. RESULTS: Prepubertal children and adolescent athletes displayed higher raw bioelectrical values (R, Xc, and Z) than pubertal athletes, even after adjusting for covariates. The BIVAc approach yielded higher values across all adjustment models (p<0.01). In contrast, no significant differences were observed between prepubertal and pubertal groups in the BIVAsp approach, even after adjusting for all models (p>0.05). CONCLUSIONS: Prepubertal children and adolescent athletes exhibit higher values of R, Xc, and Z than pubertal athletes, both in raw analyses and when normalized for height (BIVAc). However, when normalized by body circumferences and height (BIVAsp), these differences were no longer significant, suggesting that height normalization preserves maturational differences, whereas normalization by body circumferences attenuates them.