Inspiratory muscle training may benefit respiratory function, cardiocirculatory parameters, quality of life and functionality in neuromuscular diseases. This pilot study aimed to demonstrate the POWERbreathe® inspiratory muscle training effects on maximum inspiratory pressure (PImax), heart rate (HR) and HR variability, as well as the quality of life impairment and functionality in patients with Amyotrophic Lateral Sclerosis (ALS). A pilot single-blinded, non-randomized controlled clinical trial was carried out. A total of 20T ALS patients were enrolled and divided into experimental (n = 10) and control (n = 10) groups. The experimental group received POWERbreathe® inspiratory muscle training in conjunction with usual care, and the control group received only usual care for 8 weeks. PImax (measured by POWERbreathe® KH1), HR and HR variability (evaluated by Polar H7), quality of life impairment [measured by the Amyotrophic Lateral Sclerosis Assessment Questionnaire—40 items (ALSAQ-40)] and functionality [assessed by the ALS Functional Rating Scale Revised (ALSFRS-R)] were collected at baseline and after 8 weeks of intervention. We detected statistically significant differences (p < 0.05) with an effect size ranging from medium to large (Cohen’s d = 0.72−1.37); relative to the control group, the experimental group had an increased PImax (mean difference = 10.80 cm H2O; 95% CI = 3.42−18.17) and ALSFRS-R score (mean difference = 5.30 points; 95% CI = −0.03−10.63) and reduced HR (mean difference = −8.80 beats-per-minute; 95% CI = −20.27−2.67) and R-R interval (mean difference = 78.30 ms; 95% CI = 2.89−153.70). POWERbreathe® inspiratory muscle training, in addition to usual care, may improve inspiratory strength and heart rate in patients with ALS. These results encourage larger and longer trials investigating potential clinically relevant benefits of inspiratory muscle training to these patients over the disease course.
Keywords: amyotrophic lateral sclerosis; breathing exercises; disability evaluation; heart rate; maximal respiratory pressures; quality of life.