Comparative analysis of body composition and pulmonary function in elite male deaf endurance athletes – track and field and road cycling

The physiological determinants of respiratory function in elite athletes with hearing impairment remain unexplored. It is unknown whether sport-specific adaptations or the unique neurophysiology of deafness primarily govern their pulmonary performance, and if standard spirometric criteria are applicable. This study aimed to conduct the first comprehensive multivariate characterization of anthropometric and training-related predictors of pulmonary function in elite deaf athletes, comparing disciplines with contrasting physiological demands. Thirty-three elite male deaf athletes (track-and-field, n = 12; road cycling, n = 21) underwent rigorous spirometry and body composition analysis. We employed bivariate correlations, multiple linear regression, a novel multivariate Euclidean distance analysis, and a test-retest reliability assessment to identify independent predictors of key respiratory parameters and quantify overall physiological distinctness. We identified a unique spirometric signature in deaf athletes, characterized by abbreviated forced expiration times (FET100% < 6s) and elevated extrapolated volume (VEXT), suggesting a neurophysiological adaptation in respiratory motor control due to absent auditory feedback. Multivariate analysis confirmed distinct, sport-specific physiological profiles (between-group Euclidean distance: 6.91). The determinants of lung function were fundamentally different: in track athletes, Fat-Free Mass was the dominant predictor of FEV1 (β = 0.95, R² = 0.92, p = 0.002), reflecting strength-oriented adaptations. In cyclists, body height was the primary determinant (β = 0.71, R² = 0.86, p < 0.001), indicating a structural influence. Body height exerted opposing effects on MEF25% between sports (track: β = − 1.45; cycling: β = 0.81), further underscoring discipline-specific pathways. Track athletes also demonstrated superior technical proficiency in spirometry execution (83.3% “Excellent” maneuvers vs. 66.7% in cyclists). Crucially, an analysis of measurement reliability quantitatively corroborated this difference through superior test-retest reliability metrics: they showed a lower Minimal Detectable Change for FEV1 (MDC95 = 0.11 L vs. 0.31 L in cyclists), while primary outcomes (FVC, FEV1) demonstrated excellent reliability (ICC > 0.90) in both groups. The respiratory physiology of elite deaf athletes is not defined by auditory deficit but by sport-specific adaptation and a unique respiratory neurology. Our findings challenge the applicability of standard pulmonary models and criteria to this population. Coaches and clinicians are recommended to adopt discipline-specific frameworks and tailored communication for respiratory assessment and performance optimization in deaf athletes, moving beyond a one-size-fits-all approach.