Anthropometric Profile, Body Composition, and Game Performance of the Mexican Professional Basketball League Champion Team During the 2025–2026 Basketball Champions League Americas: A Cross-Sectional Study

Background and Objectives: Basketball imposes a marked positional division of labour, and body size, somatotype and body composition are among the variables most consistently monitored in professional practice. Whole-roster studies pairing a complete kinanthropometric assessment with official competition statistics from the same competitive window are nevertheless scarce, and Latin American professional teams are almost absent from this literature. This study aimed (i) to describe the anthropometric profile, somatotype, body composition and field-test aerobic performance of the champion team of the Mexican professional league during the 2025–2026 Basketball Champions League Americas, and (ii) to explore, as a hypothesis-generating exercise, the association between these characteristics and per-game output from official box scores. We hypothesised a priori that any such association would be largely explained by playing position rather than by a direct effect of body build on performance. Methods: A cross-sectional census of the entire active roster (n = 18), assessed on a single day three days before the first of the eight games analysed, was carried out. Sixteen players completed a full International Society for the Advancement of Kinanthropometry (ISAK) profile with Heath–Carter somatotype and multi-frequency bioelectrical impedance analysis, 16 had official box-score data and 14 had both; 13 completed the 20 m multistage shuttle run. The shuttle-run result is reported as the maximal aerobic speed attained (km·h−1); the maximal oxygen uptake (VO2max) derived from it is a field-test estimate, used only as a within-team ranking and never as an absolute physiological value. Sixty Spearman correlations were pre-specified as exploratory and are reported with bootstrap and Fisher z 95% confidence intervals and Benjamini–Hochberg false-discovery-rate control. Results: Players were tall and lean (stature 194.6 ± 9.1 cm; body mass 92.8 ± 13.6 kg; body mass index (BMI) 24.4 ± 2.2 kg/m2; Σ8 skinfolds 82 ± 29 mm), with a balanced-mesomorph somatotype (2.5–4.5–3.0) and a high mean phase angle (8.8 ± 0.8°). Twelve correlations reached p < 0.05, but only one survived multiplicity control: maximal aerobic speed with rebounds per game (ρ = −0.86, p < 0.001, q = 0.018); this association disappeared when aerobic power was expressed in absolute terms (ρ = −0.17, p = 0.587), identifying body size as its source. Stature, body mass, Σ8 skinfolds and endomorphy were inversely associated with assists per game (ρ = −0.60 to −0.70; p = 0.006–0.022), and BMI, mesomorphy, ectomorphy and phase angle with field-goal percentage (ρ = −0.57 to +0.69; p = 0.007–0.039), but intervals were wide, q ≥ 0.078 for these associations, and field-goal percentage rested on an unknown number of attempts. Conclusions: This championship roster showed the tall, long-limbed, balanced-mesomorphic profile of the elite game and was markedly less endomorphic than Mexican athletic reference values. The a priori hypothesis was supported: every association was interpretable as an expression of playing position, and the single association surviving multiplicity control proved to be an artefact of body-size standardisation. Within-team anthropometry–output correlations should not be used to inform selection or playing-time decisions.