Resistance training prevents deterioration in quadriceps muscle function during acute exacerbations of chronic obstructive pulmonary disease.

RATIONALE Exacerbations of chronic obstructive pulmonary disease (COPD) acutely reduce skeletal muscle strength and result in long-term loss of functional capacity. OBJECTIVES To investigate whether resistance training is feasible and safe and can prevent deteriorating muscle function during exacerbations of COPD. METHODS Forty patients (FEV(1) 49 +/- 17% predicted) hospitalized with a severe COPD exacerbation were randomized to receive usual care or an additional resistance training program during the hospital admission. Patients were followed up for 1 month after discharge. Primary outcomes were quadriceps force and systemic inflammation. A muscle biopsy was taken in a subgroup of patients to assess anabolic and catabolic pathways. MEASUREMENTS AND MAIN RESULTS Resistance training did not yield higher systemic inflammation as indicated by C-reactive protein levels and could be completed uneventfully. Enhanced quadriceps force was seen at discharge (+9.7 +/- 16% in the training group; -1 +/- 13% in control subjects; P = 0.05) and at 1 month follow-up in the patients who trained. The 6-minute walking distance improved after discharge only in the group who received resistance training (median 34; interquartile range, 14-61 m; P = 0.002). In a subgroup of patients a muscle biopsy showed a more anabolic status of skeletal muscle in patients who followed training. Myostatin was lower (P = 0.03) and the myogenin/MyoD ratio tended to be higher (P = 0.08) in the training group compared with control subjects. CONCLUSIONS Resistance training is safe, successfully counteracts skeletal muscle dysfunction during acute exacerbations of COPD, and may up-regulate the anabolic milieu in the skeletal muscle. Clinical trial registered with www.clinicaltrials.gov (NCT00877084).