Respiratory Muscle Strength and Ventilatory Function Outcome: Differences Between Trained Athletes and Healthy Untrained Persons.

It is known that the maximum mouth inspiratory pressure (MIP) and expiratory pressure (MEP) vary with age, weight, height, and skeletal muscle mass. However, the influence of physical training on ventilatory function outcomes is an area of limited understanding. The aim of this study was to investigate the respiratory muscle strength and its relation to spirometry variables in untrained healthy persons versus trained athletes.

Loading and unloading breathing during exercise: respiratory responses and compensatory mechanisms.

To characterize the ventilatory responses to resistive loading or unloading, we studied the effects of breathing 79% helium-21% oxygen (He-O⊂2), 79% argon-21% oxygen (Ar-O⊂2) and 79% SF⊂6-21% oxygen (SF⊂6-O⊂2) on the volume-time parameters, end-tidal partial pressure of CO⊂2 (PETCO⊂2), mouth pressure (P⊂Im), work of breathing (W⊂I), central inspiratory activity (dP/dt⊂I), and electromyographic activity of parasternal inspiratory muscles (EMGps) in 10 normal subjects at rest and during short-time steady-state exercise. There were no significant changes in tidal volume (V⊂T), breathing frequency (f), inspiratory (T⊂I) and expiratory (T⊂E) durations, minute ventilation (V⊂E), and P⊂ET CO⊂2 when air was replaced by He-O⊂2 or SF⊂6-O⊂2 at rest. V⊂E and P⊂ET CO⊂2 were not significantly different after replacement of air by He-O⊂2 or SF⊂6-O⊂2 during exercise.