Home-Based Inspiratory Muscle Training as Stand-Alone Therapy in COPD: A Randomized Sham-Controlled Trial Assessing Novel and Established Training Methods

This randomized controlled trial evaluated the effectiveness of two home-based, stand-alone inspiratory muscle training (IMT) modalities - inspiratory flow-resistive loading with biofeedback (IRFL) and mechanical threshold loading (MTL) - compared to a sham MTL group for improving inspiratory muscle performance and functional exercise capacity in COPD patients. Thirty-six COPD patients trained at home for 8 weeks under remote monitoring. Primary outcomes included inspiratory muscle performance assessed <i>via</i> the Test of Incremental Respiratory Endurance (TIRE), functional exercise capacity, lung function, and other COPD-related measures. Both the TIRE IRFL and MTL groups showed significant improvements in inspiratory muscle strength compared to the sham MTL group (<i>p</i> < 0.05). Additionally, the IRFL with biofeedback group demonstrated significant gains in inspiratory muscle work capacity and 6MWT distance compared to both the MTL and sham groups (<i>p</i> < 0.05). No adverse events were reported, and adherence to training protocols was high across all groups. This study supports home-based IMT as a feasible, effective stand-alone intervention for COPD patients, particularly for those who face barriers in accessing traditional pulmonary rehabilitation programs. TIRE IFRL showed superior benefits in enhancing inspiratory muscle function and overall functional exercise capacity compared to fixed-load IMT.