The kinanthropometric and pulmonary determinants of global respiratory muscle strength and endurance indices in an athletic population

The morphological determinants of respiratory muscle (RM) strength and endurance in non-athletic populations are well documented, but are lacking in athletic populations. The purpose of this study was to determine the kinanthropometric and pulmonary predictors of RM strength and endurance. 160 athletes (103 men) were recruited from eight different sports to participate in the study. All subjects underwent a series of kinanthropometric and RM function assessments during a single visit to the laboratory. RM function assessments included the flow-volume curve test to assess pulmonary function, maximum voluntary ventilation (MVV) to assess RM endurance and maximum inspiratory mouth pressure (MIP) and maximum expiratory mouth pressure (MEP) to assess RM strength. Multiple regression analyses revealed that gender, mesomorphy and exercise sessions per week predicted 35% (SEE = 26.6 cmH₂O) of the variance in inspiratory muscle strength (MIP). Gender and mesomorphy predicted 24% (SEE = 28.3 cmH₂O) of the variance in expiratory muscle strength (MEP), while gender, relative sitting height, forced expiratory volume in 1 s (FEV₁) and peak expiratory flow rate (PEFR) predicted 78% (SEE = 18.2 L min⁻¹) of the variance in RM endurance (MVV). Although the reference equations are still not adequate to predict MIP and MEP in an athletic population, they provide more suitable reference values than previously reported. The predicted values derived from the equation for MVV can be applied as adequate reference values for athletic populations.