Anthropometric profile of youth water polo players after, according to the maturity offset and bia vector migration after an acute bout of training

Purpose: (1) To describe the anthropometrical and bioelectrical characteristics of young water polo players according to biological maturity; (2) to evaluate, with the bioelectrical impedance vector analysis (BIVA) method, the hydration status before and after a typical training session for regional youth championship participants. Methods: Twenty-four young water polo players (age: 13.30 ± 0.55 years) performed a training session. During the training session, they drank about lt. of water, ad libitum. Bioelectrical variables (R, resistance; Xc, reactance; PA, phase angle; Z, impedance) and body mass (BM) were measured pre-and post-training. Stature and sitting height were also assessed before training to normalize bioelectrical values and to classify players as growth peak notachieved (GPNA) or growth peak achieved (GPA), according to the distance from peak height velocity in years (YPHV). BIVA was used to characterize 1) the distribution pattern of the bioelectrical vector (BIA vector) for both groups and 2) pre- to post-training BIA vectormigration. Results: The BIVA point graph indicates that half of the sample fell inside the 50% tolerance ellipse of the reference population. The remaining participants were distributed outside the 50% and 75% tolerance ellipses, with the majority on the left quadrant. The BIA vector comparison showed that both subgroups differed statistically from the reference population, and the sub-groups were also statistically different. Following training, a reduction was found in BM (about 400 gr; 0, 7%). However, the shortening of the BIA vector does not align with the change in BM. Conclusions: The study suggests that biological maturity influences the BIA vector position on the RXc graph. Furthermore, training causes only mild dehydration is not detectable with the BIVA method when it’s concurrent with fluid intake during training.