Peripheral muscle strength training in COPD: a systematic review.

BACKGROUND: Skeletal muscle weakness, and the associated impact on exercise tolerance, provides a strong theoretical rationale for strength training intervention for people with COPD.Aim: The purpose of this review was to examine systematically the current evidence for peripheral muscle strength training in people with COPD. METHOD: Empirical trials and reviews relating to strength training in COPD were obtained by searching electronic databases and citation tracking, using the keywords of COPD with strength/resistance training and skeletal muscle. Two reviewers completed data extraction and quality assessment independently, using the PEDro (physiotherapy evidence database) scale and a checklist for review articles. Effect sizes and 95% confidence intervals were determined for empiric trials and metaanalysis used where appropriate. RESULTS: The search strategy yielded 13 articles (9 empirical trials and 4 reviews). Strength training was found to have strong evidence for improving upper body and leg strength. However, no strong evidence for strength training was found for other outcome measures. CONCLUSIONS: Further research is required to investigate the effects of strength training on functional activities, such as balance, upper limb function, self care, and participation in daily life.