Association between intensity and type of physical activity and lung function in patients with COPD: a population-based study.

INTRODUCTION: Aerobic exercise is a cornerstone of chronic obstructive pulmonary disease (COPD) management; however, its association with lung function parameters has remained inconsistent across prior studies, and previous studies have been limited by examining physical activity (PA) as a single intensity dimension without distinguishing specific PA types. We therefore investigated the associations between PA intensity and type with lung function outcomes (FEV1, FVC, and PEF) in COPD patients and individuals with normal spirometry (FEV1/FVC ≥ 0.7 and FVC ≥ 80% of predicted), and formally tested whether these associations differ between the two groups.

METHODS: This nationwide population-based cross-sectional study included data from 14,679 participants from 2014 to 2019. All participants underwent a health survey and a series of health examinations, including a pulmonary function test. Associations between lung function and PA intensity, PA types (walking, strengthening, and aerobic exercise), and PA intensity stratified by age and sex were assessed using analysis of covariance.

RESULTS: In the COPD group, higher levels of PA were associated with increased forced expiratory volume in one second (FEV1), forced vital capacity (FVC), and peak expiratory flow (PEF) across all models. Among PA types, aerobic exercise was the only type significantly associated with improved FEV1, FVC, and PEF in COPD patients across progressively adjusted models (unadjusted; adjusted for sociodemographic and lifestyle factors; additionally adjusted for major comorbidities). Furthermore, the associations between aerobic exercise and FEV1 and FVC were significantly stronger in the COPD group than in the normal spirometry group in adjusted analyses (p for interaction = 0.0297 and 0.0069, respectively, in the fully adjusted model), whereas no significant interaction was observed in the unadjusted model. No significant associations between PA intensity and lung function were observed in COPD patients when stratified by age or sex.

DISCUSSION: Among PA types, aerobic exercise was the only type significantly associated with improved FEV1, FVC, and PEF in COPD patients after full covariate adjustment, and its associations with FEV1 and FVC were significantly stronger in the COPD group than in individuals with normal lung function. These findings support the inclusion of structured aerobic exercise as a core component of COPD management.