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.