Effects of fast expiration exercises without pressure on the respiratory muscle strength of healthy subjects

[Purpose] The aim of this investigation was to determine the effects of 4 weeks of fast expiration exercises performed without pressure on respiratory muscle strength. [Subjects and Methods] Respiratory muscle strength of the training group that performed fast expiration exercises (n=12) was compared with that of a control group that performed no exercises (n=12). The fast expiration exercises were performed using a peak expiratory flow meter device and consisted of 20 fast expiration exercises performed 3 times per week for 4 weeks. Maximal expiratory and inspiratory pressures were evaluated as respiratory muscle strength using a spirometer pre- and post- intervention. [Results] There were significant increases in maximal expiratory pressure from 76.9 ± 29.1 to 96.1 ± 37.5 cmH2O and maximal inspiratory pressure from 80.8 ± 36.6 to 95.3 ± 37.6 cmH2O in the training group, but there was no significant difference in respiratory muscle strength between pre- and post-intervention in the control group. [Conclusion] Fast expiration exercises may be beneficial for increasing respiratory muscle strength. The findings of this study should be considered when prescribing a variation of the expiratory muscle strength training, as part of a pulmonary rehabilitation program.