RESUMO
BACKGROUND AND OBJECTIVE: Skeletal muscle dysfunction contributes to exercise limitation in patients with chronic obstructive pulmonary disease (COPD). Strength training increases muscle strength and muscle mass, but there is an ongoing debate on the additional effect concerning the exercise capacity. The purpose of this study was to compare the effects of three different exercise modalities in patients with COPD including endurance training (ET), progressive strength training (ST) and the combination of strength training and endurance training (CT). DESIGN: A prospective randomized trial. METHODS: Thirty-six patients with COPD were randomly allocated either to ET, ST, or CT. Muscle strength, cardiopulmonary exercise testing, lung function testing and quality of life were assessed before and after a 12-week training period. RESULTS: Exercise capacity (Wmax) increased significantly in all three training groups with increase of peak oxygen uptake (VO2peak) in all three groups, reaching statistical significance in the ET group and the CT group. Muscle strength (leg press, bench press, bench pull) improved in all three training groups, with a higher improvement in the ST (+39.3%, +20.9%, +20.3%) and the CT group (+43.3%, +18.1%, +21.6%) compared to the ET group (+20.4%, +6.4%, +12.1%). CONCLUSIONS: Progressive strength training alone increases not only muscle strength and quality of life, but also exercise capacity in patients with COPD, which may have implications in prescription of training modality. CLINICALTRIALS.GOV IDENTIFIER: NCT01091623.