Effects of Inspiratory Muscle Training and Yoga Breathing Exercises on Respiratory Muscle Function in Institutionalized Frail Older Adults: A Randomized Controlled Trial

Background: In older adults, respiratory function may be seriously compromised when a marked decrease of respiratory muscle (RM) strength coexists with comorbidity and activity limitation. Respiratory muscle training has been widely studied and recommended as a treatment option for people who are unable to participate in whole-body exercise training (WBET); however, the effects of inspiratory muscle training and yoga breathing exercises on RM function remain unknown, specifically in impaired older adults. Purpose: To evaluate the effects of inspiratory threshold training (ITT) and yoga respiratory training (YRT) on RM function in institutionalized frail older adults. Methods: Eighty-one residents (90% women; mean age, 85 years), who were unable to perform WBET (inability to independently walk more than 10 m), were randomly assigned to a control group or one of the 2 experimental groups (ITT or YRT). Experimental groups performed a supervised interval-based training protocol, either through threshold inspiratory muscle training device or yoga breathing exercises, which lasted 6 weeks (5 days per week). Outcome measures were collected at 4 time points (pretraining, intermediate, posttraining, and follow-up) and included the maximum respiratory pressures (maximum inspiratory pressure [MIP] and maximum expiratory pressure [MEP]) and the maximum voluntary ventilation (MVV). Results: Seventy-one residents completed the study: control (n = 24); ITT (n = 23); YRT (n = 24). The treatment on had a significant effect on MIP YRT (F-6,F-204 = 6.755, P < .001, eta(2) = 0.166), MEP (F-6,F-204 = 4.257, P < .001, eta(2) = 0.111), and MVV (F-6,F-204 = 5.322, P < .001, eta(2) = 0.135). Analyses showed that the YRT group had a greater increase of RM strength (MIP and MEP) and endurance (MVV) than control and/or ITT groups. Conclusion: Yoga respiratory training appears to be an effective and well-tolerated exercise regimen in frail older adults and may therefore be a useful alternative to ITT or no training, to improve RM function in older population, when WBET is not possible.