Beneficial effects of a novel inspiratory muscle training device on respiratory muscle strength and submaximal functional capacity in community-dwelling older Thai adults: a randomized controlled trial

Older adults encounter progressive deterioration of all organ systems. Disease development reportedly increases with age, resulting in decreased physical performance in terms of aerobic endurance, muscular strength, and physical ability. Inspiratory muscle training (IMT) is commonly performed to improve cardiorespiratory fitness. Therefore, this study aimed to develop a resistive inspiratory muscle and determine the effect of inspiratory muscle training on respiratory muscle strength and functional capacity in older adults. Methods Sixty older adults (age: ≥60 years), both males and females, were enrolled. All participants performed a respiratory muscle strength test (maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP)) and a 6-minute walking distance test ( i.e. , submaximal functional capacity) before and after an 8-week intervention program. An inspiratory muscle training device, the Breath Trainer, an air-resistive respiratory training device connected to a smartphone via Bluetooth, was developed. Each individual was required to attach the Breath Trainer to the lower costal part of the chest wall during the training program. The breathing training group used a Breath Trainer set to 40% MIP, whereas the sham-IMT performed a training set to 0% MIP. In both groups, training involved 15 repetitions, three sessions/day, and 5 days/week. An intention-to-treat analysis was performed, followed by a two-way mixed repeated analysis of variance (ANOVA). Results Between-group difference, the breathing training group exhibited improved respiratory muscle strength (MIP = 19.56 ± 4.54 cmH 2 O, p < .001, MEP = 18.87 ± 43.41 cmH 2 O, p < .001) and submaximal functional capacity (56.63 ± 17.97 meters, p = .003) compared with the sham-IMT, following the 8-week program. Discussion An 8-week program with the Breath Trainer could improve respiratory muscle strength and submaximal functional capacity in older adults.