The Effects of Interval Respiratory Muscle Training on Athletic Performance

This study evaluated the effects of a 4-week respiratory muscle training (RMT) program using constant versus incremental threshold resistance on respiratory muscle strength, pulmonary function, extremity strength, and aerobic/anaerobic endurance in trained athletes. Participants were randomized into two groups: the Constant IMT group (trained at a fixed 40% of maximal inspiratory pressure \[MIP\]) and the Incremental IMT group (progressing weekly from 50% to 80% of MIP). Both groups trained twice daily, 5 days per week (2 sets of 30 breaths/day) for 4 weeks. Standardized physiological, spirometric, and athletic performance tests were assessed at baseline and post-intervention.