Inspiratory muscle training (IMT) in patients with asthma: A pilot study

Abstract

Background: Patients with asthma present increased inspiratory muscle work, especially during exercise. Aim: To evaluate the effects of Inspiratory muscle training (IMT) on lung function, inspiratory endurance and functional capacity in patients with asthma. Methods: Double-blind control design. Ten patients (four males, 43±11 years) with controlled mild-severe asthma were randomised in two groups [IMT group (IMT-G) and controls (CG)]. Both received two educational sessions on asthma care. IMT-G used PowerBreathe® to perform IMT with a minimum load of 50% of maximal inspiratory pressure (MIP) weekly adjusted, six sets of 30 breaths/day, five days/week. Lung function, MIP, inspiratory endurance and functional capacity (Shuttle test) were assessed at baseline and after eight weeks. ANOVA 2x2 with post-hoc LSD was used for comparisons, α=0.05. Results: Improvements were significant higher (p 2 0 [88% (IMT-G) vs 19% (CG)] and work-J [486% (IMT-G) vs 28% (CG)]. Significant differences between groups were found in number of breaths [31±28 to 96±21 (IMT-G) vs 25±9 to 25±9 (CG); p=0.008] and time-s [214±150 to 511±146 (IMT-G) vs 205±43 to 192±57 (CG); p=0.040] during inspiratory endurance test. No significant differences were observed in lung function and functional capacity. Conclusions: Our data suggest that inspiratory muscle training can improve inspiratory endurance and time to fatigue in patients with asthma. Partially suported by: CAPES, CNPq and FAPEMIG - Brazilian agencies.