Author(s): SIATKOWSKI, S., SIKORA, M., ZEBROWSKA, A., HALL, B., GRABOWSKA, A., Institution: AWF KATOWICE, Country: POLAND, Abstract-ID: 1942

INTRODUCTION:
Strength and combat sports are associated with marked hypertrophy of the trunk and cervical musculature. These structural adaptations may increase mechanical loading of the chest wall and upper airways, potentially altering respiratory system mechanics. Athletes with pronounced muscular development also appear to have an increased prevalence of sleep-disordered breathing, including obstructive sleep apnea (OSA). The functional implications of these adaptations, however, remain insufficiently defined. The aim of this study was to characterize respiratory system mechanics in strength-trained athletes using spirometry, static lung volume assessment (TLC and RV), and the forced oscillation technique (FOT), and to examine their relationship with nocturnal respiratory parameters.
METHODS:
Twenty athletes engaged in strength and/or combat sports and 20 matched controls were enrolled. All participants underwent spirometry, static lung volume measurements (including total lung capacity [TLC] and residual volume [RV]) using a mouthpiece-based plethysmographic system, and assessment of respiratory impedance with FOT. Overnight polygraphic sleep studies were performed in all subjects. Associations between respiratory mechanics parameters, body composition indices, and markers of sleep apnea severity were analyzed.
RESULTS:
Athletes with substantial muscular development demonstrated alterations in respiratory mechanics, particularly in FOT-derived resistance and reactance parameters. These abnormalities were not consistently reflected in conventional spirometric indices. Altered impedance parameters were associated with the presence and severity of sleep apnea. Static lung volumes showed no uniform spirometric pattern explaining these changes, suggesting functional rather than overt restrictive or obstructive impairment.
CONCLUSION:
Muscular hypertrophy characteristic of strength-based disciplines may modify respiratory system mechanics and contribute to early functional alterations that remain undetected by standard spirometry. FOT appears capable of identifying subclinical changes in airway resistance and elastic properties prior to overt spirometric abnormalities and potentially before the clinical manifestation of sleep apnea. These findings suggest a physiological trade-off between adaptation to high-intensity training and optimal respiratory function.