Basketball performance is influenced by cardiorespiratory fitness and body composition. However, evidence regarding the ability of maximal oxygen uptake (VO2max) to distinguish between competitive levels remains inconsistent. This study aimed to examine differences in cardiorespiratory fitness and body composition between professional and amateur basketball players and to explore their contribution to variability in relative VO2max. This pilot study also informed sample size estimation for future studies. A cross-sectional study was conducted with 12 professional (21.0 ± 2.3 years; BMI: 25.37 ± 3.04 kg/m2) and 12 amateur (22.6 ± 1.7 years; BMI: 26.83 ± 3.24 kg/m2) male basketball players. Absolute and relative VO2max, ventilatory thresholds, and body composition (five-component fractionation) were assessed. Between-group comparisons were performed using Welch’s t-tests, effect sizes were estimated using Hedges’ g, and covariance analyses were adjusted for height and body fat percentage. No statistically significant differences were observed in relative VO2max between groups. However, the absolute second ventilatory threshold was significantly higher in professional players, and absolute VO2max showed a large effect size favoring this group. Professionals also showed lower body fat percentage and greater fat-free mass (p < 0.01; g ≈ 1.2). These findings suggest that body composition differences may partly explain variability in relative VO2max between competitive levels.
Pezo-Mora et al. (Sun,) studied this question.