###### Abstract  
The main purpose of this study was to evaluate the morphological characteristics of a sample of young international elite basketball players to create new reference values, using both somatotype and Bioelectrical Impedance Vector Analysis (BIVA). Moreover, we analyze the influence of age and maturation on anthropometric characteristics. Anthropometric measures (stature, body mass, body circumferences, skinfold thicknesses, and diameters) have been collected in a sample of 153 young basketball players of different age categories. From these measures, the endo-, eco-, and mesomorph somatotypes components were calculated. In addition, impedance measurements were performed with a hand-to-foot bioimpedance analyser, and, subsequently, BIVA was carried out and biological maturity was estimated. A principal component analysis (PCA) has been assessed to reduce somatotype dimensionality. Almost all the collected variables differed between age groups. As regards the somatotype, the majority of the athletes were mesomorph-ectomorphal and the degree of homogeneity of the sample was high; the somatotype is aligned with that of the older athletes. Strong relationships were observed between mesomorphy, age, and bio-electric phase angle. Moreover, a tolerance ellipse graph was proposed as a reference for young elite athletes in basketball, and a new PCA-based method with one component was created to synthesize somatotype contents (eigenvalue = 2.42, R\({}^{2}\) = 0.807). Reference values for basketball players are needed by researchers, coaches, and practitioners for the process of talent identification and development. There are too many biological features to easily account for during growth, and field personnel need synthetic and more reliable approaches. s _Applied sciences_  
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Footnote 1: email: _Applied sciences_  
color=green!20,color=green! evaluating suitable somatic parameters for a given sport [1]. Male basketball players are likely to display a mesomorph somatotype, but there are also professional players from top teams with mixed and balanced somatotypes [5]. However, the somatotype varies during growth and maturation: younger competitors appeared more ectomorphic than professional players, who tend to manifest higher mesomorphic values [1]. It should be emphasized that the somatotype must consider all three components together and not separately. This could cause issues when analyzing the relationships between the somatotype and other parameters, as the components are often considered individually. Another important factor to evaluate is body composition since it influences the training and performance of athletes [6]. However, many factors influence its evaluation, such as age, maturation and constitution, and these should be considered. In addition, many techniques are available for body composition assessment in basketball samples, which range from simple indirect measures to more sophisticated direct volumetric measurements [7]. The use of laboratory methods is limited due to their cost and complexity. In light of this, portable instruments such as bioelectrical impedance analysers (BIA) have become popular among athletes thanks to their ease of use, cost-effectiveness, and portability [8]. BIA is a non-invasive method based on the electric properties of biological tissue in response to alternate low-voltage current flow. The biological impedance is defined as the ability of human tissues to impede electric current passage [9]. Biological tissues act as conductive interfaces that oppose the current flow (resistance) and frequency (reactance): R represents the opposition to the flow of an alternating current through intra- and extracellular ionic solution, whereas Xc represents the capacitive component of tissue interfaces, cell membranes, and organelles [10]. Due to the relatively low cost and the portability of the analyser, many studies on body composition and clinical condition evaluations have been carried out using this technique.