Effects of flow and resistive training on respiratory muscle endurance and strength.

This study was conducted to ascertain whether resistive or flow type training would better improve both strength and endurance in the respiratory muscles of healthy subjects. Subjects performed a battery of respiratory strength and endurance tests before and after training, which consisted of either control, cycling exercise (E), inspiratory loading (IL), expiratory loading (EL), or hyperventilation (H) training for 4 weeks. Maximal sustained ventilation increased after training in the E and H groups. Both IL and H improved inspiratory fatigue resistance. IL improved maximal inspiratory pressure. No significant changes were found in maximal expiratory pressure although E, EL, and H tended to improve. There was no statistical difference in maximal voluntary ventilation between groups after training, but the H group alone did increase. This study suggests that respiratory muscle strength and endurance can be improved with flow or resistive training. Flow type training improves both flow and resistive tests while resistive training appears to affect only strength and resistive type measurements.