Effect of Exercise Order During Pulmonary Rehabilitation on Muscle Strength in Patients With COPD

Chronic Obstructive Pulmonary Disease (COPD) is a chronic multisystem disease frequently associated with peripheral muscle dysfunction, which is strongly linked to prognosis and survival. Pulmonary rehabilitation is a cornerstone of COPD management and includes both cardiorespiratory endurance training and muscle strengthening exercises. Although these components are routinely combined within rehabilitation programs, the optimal order in which they should be performed during the same training session remains unclear. In healthy individuals, performing endurance and strength exercises in different sequences within a single session may influence muscular adaptations, a phenomenon referred to as the intra session interference effect. This effect has never been studied in patients with COPD undergoing pulmonary rehabilitation. Given the high prevalence and clinical importance of muscle weakness in COPD, optimizing exercise prescription may improve functional outcomes and long term benefits. This multicenter randomized controlled trial aims to compare two pulmonary rehabilitation strategies that differ only in the order of exercise administration. Participants with moderate to severe COPD will be randomly assigned to perform either muscle strengthening before endurance training or endurance training before muscle strengthening during each rehabilitation session. The primary objective is to evaluate the impact of exercise order on lower limb muscle strength, assessed by the Five Times Sit to Stand test at the end of the rehabilitation program. Secondary objectives include assessment of exercise capacity, dyspnea, muscle and inflammatory biomarkers, tolerance, and adherence to the rehabilitation program, as well as follow up evaluations up to 12 months after completion. The results of this study are expected to provide evidence to optimize pulmonary rehabilitation programs for patients with COPD and to inform clinical practice regarding exercise sequencing.