The effects of 8 weeks of inspiratory muscle training on the balance of healthy older adults: a randomized, double-blind, placebo-controlled study

To examine the effects of 8-week unsupervised, home-based inspiratory muscle training (IMT) on the balance and physical performance of healthy older adults. Fifty-nine participants (74 +/- 6 years) were assigned randomly in a double-blinded fashion to either IMT or sham-IMT, using a pressure threshold loading device. The IMT group performed 30-breath twice daily at similar to 50% of maximal inspiratory pressure (MIP). The sham-IMT group performed 60-breaths once daily at similar to 15% MIP; training was home-based and unsupervised, with adherence self-reported through training diaries. Respiratory outcomes were assessed pre-and postintervention, including forced vital capacity, forced expiratory volume, peak inspiratory flow rate (PIFR), MIP, and inspiratory peak power. Balance and physical performance outcomes were measured using the shortened version of the Balance Evaluation System test (mini-BEST), Biodex +/- postural stability test, timed up and go, five sit-to-stand, isometric " sit-up" and Biering-Sorensen tests. Between-group effects were examined using two-way repeated measures ANOVA, with Bonferroni correction. After 8-week, the IMT group demonstrated greater improvements (P = 0.05) in: PIFR (IMT = 0.9 +/- 0.3 L sec(-1); sham-IMT= 0.3 L sec(-1)); mini-BEST (IMT = 3.7 +/- 1.3; sham-IMT = 0.5 +/- 0.9) and Biering-Sorensen (IMT = 62.9 +/- 6.4 sec; sham-IMT = 24.3 +/- 1.4 sec) tests. The authors concluded that twice daily unsupervised, home-based IMT is feasible and enhances inspiratory muscle function and balance for community-dwelling older adults.