Effect of water exercise on the respiratory function and functional capacity of patients with COPD: a randomized controlled trial

Abstract

Introduction: Chronic obstructive pulmonary disease (COPD) not only restricts airflow but also induces systemic manifestations in individuals with the disease. Objective: To evaluate the effect of a water-based aerobic exercise program on respiratory muscle strength, thoracic mobility, dyspnea, and functional capacity in patients with COPD. Methods: We conducted a blind randomized controlled trial with 22 patients with COPD, dividing them into a control group (CG) and a training group (TG). The TG participated in 24 sessions of a water aerobic exercise program, while the CG only participated in the evaluations. Maximal respiratory pressure (MRP), dyspnea, and functional capacity were measured. Results: When comparing the MRP values (cmH2O) in the pre- and post-training conditions, the results revealed a significant improvement in the TG [maximal inspiratory pressure (MIP): 74.8 ± 15.3 vs. 83.9 ± 17.2; maximal expiratory pressure (MEP): 141.5 ± 30.7 vs. 157.6 ± 32.9], whereas no difference was observed for the CG (MIP: 55.5 ± 21.8 vs. 54.4 ± 18.4; MEP: 116.2 ± 40.3 vs. 109.3 ± 38.9). Regarding thoracic mobility in the pre- and post-training conditions, no significant difference was found for the CG, whilst for the TG there was a significant increase at the axillary level (cm) (5.9 ± 1.8 vs. 7.7 ± 1.1). With respect to functional capacity, there was a significant increase in walking distance during the six-minute walking test only in the TG when comparing pre- and post-training conditions (462.1 ± 62.9 vs. 538.5 ± 63.7). Lastly, the dyspnea results demonstrated that after the training period there was a major reduction in the scores of Medical Research Council (3.1 ± 0.8 vs. 1.9 ± 0.7) and Borg CR-10 scales (5.2 ± 0.8 vs. 3.7 ± 0.3) only for the TG. Conclusion: The water aerobic exercise training promoted beneficial changes in respiratory muscle strength, thoracic mobility, functional capacity and dyspnea among patients with COPD.