Feasibility of a 4-week combined supervised and home-based exercise program for patients with nontuberculous mycobacterial pulmonary disease: A single-center, single-arm feasibility study

Background Nontuberculous mycobacterial pulmonary disease (NTM-PD) is associated with functional decline and limited treatment options, highlighting the need for adjunctive exercise interventions. This study aimed to evaluate the feasibility, safety, and preliminary effects of a 4-week combined supervised and home-based exercise program for patients with NTM-PD. Methods This single-arm feasibility study included 23 outpatients with NTM-PD. The intervention comprised weekly supervised sessions and daily home-based aerobic and resistance training over 4 weeks. The primary outcomes were feasibility parameters (retention, adherence, and safety). The exploratory outcomes included cardiorespiratory fitness (VO₂max), functional capacity (6-min walk distance, sit-to-stand test), muscle strength, pulmonary function, body composition, and health-related quality of life (Quality of Life-Bronchiectasis domains). Results Of the 23 enrolled participants, 19 (82.6%) completed the study. All predefined feasibility thresholds were achieved: retention 82.6% (≥ 80% threshold), supervised-session adherence 100% (≥ 80% threshold), and home-based adherence 73.5% (≥ 70% threshold). No serious adverse events occurred. Modest functional improvements were observed: 6-min walk distance increased by 20 m (p = 0.008), and sit-to-stand performance improved by 3.5 repetitions (p = 0.010). VO₂max showed minimal changes, although valid measurements were obtained in only 10/18 participants. Health-related quality of life showed mixed results, with only the vitality domain showing a statistically significant change in distribution pattern. Pulmonary function and body composition remained unchanged. Conclusions A 4-week hybrid exercise program demonstrated feasibility, safety, and acceptability in patients with NTM-PD, with modest short-term functional gains. The brief duration of the intervention may have limited clinically meaningful improvements. These findings support the progression to long-duration randomized controlled trials with enhanced home-based exercise adherence strategies and alternative outcome measures appropriate for this population.