title: Therapeutic validity and effectiveness of supervised physical exercise training on exercise capacity in patients with chronic obstructive pulmonary disease: a systematic review and meta-analysis.
abstract: OBJECTIVE
  Our aim was to determine the effectiveness of supervised physical exercise training on exercise capacity in patients with chronic obstructive pulmonary disease taken into consideration indices such as therapeutic validity of interventions, methodological quality of studies, and exercise volume.
  
  
  METHODS
  MEDLINE, Cochrane Central Register of Controlled Trials, EMBASE, CINAHL, and PEDro databases were searched from inception until 17 July 2015 for randomized controlled trials comparing the effect of supervised exercise training vs. usual care in patients with chronic obstructive pulmonary disease. The references of included studies and review articles were hand searched for additional references and key authors of included trials were crosschecked in PubMed for any missed references.
  
  
  METHODS
  Two reviewers independently assessed therapeutic validity of exercise training and methodological quality of included studies. Overall effects were calculated using a random effects model.
  
  
  RESULTS
  A total of 13 studies involving 756 patients with chronic obstructive pulmonary disease were included. Significant differences in maximal exercise capacity (standardized mean difference 0.52, 95% CI 0.31 to 0.74) and endurance exercise capacity (standardized mean difference 0.73, 95% CI 0.50 to 0.96) in favor of physical exercise training were found. The volume of physical exercise per week, the total volume of physical exercise, or their associations did not significantly influence the effect of training.
  
  
  CONCLUSIONS
  Effects of supervised physical exercise was not significantly altered by therapeutic validity. A combination of aerobic exercise and strength training was found to be more effective than strength training or endurance training alone in increasing the 6-minute walking distance.
authors.affiliation: 1 Department of Medical Decision Making, Leiden University Medical Centre, Leiden, The Netherlands.|2 Rijnlands Rehabilitation Centre, Leiden, The Netherlands.|3 TNO Healthy Living, Leiden, The Netherlands.
authors.forename: Martijn
authors.initials: M
authors.lastname: Vooijs
authors.affiliation: 3 TNO Healthy Living, Leiden, The Netherlands.
authors.forename: Petra C
authors.initials: PC
authors.lastname: Siemonsma
authors.affiliation: 2 Rijnlands Rehabilitation Centre, Leiden, The Netherlands.
authors.forename: Inge
authors.initials: I
authors.lastname: Heus
authors.affiliation: 1 Department of Medical Decision Making, Leiden University Medical Centre, Leiden, The Netherlands.
authors.forename: Jacob K
authors.initials: JK
authors.lastname: Sont
authors.affiliation: 3 TNO Healthy Living, Leiden, The Netherlands.
authors.forename: Ton Ajm
authors.initials: TA
authors.lastname: Rövekamp
authors.affiliation: 4 Department of Epidemiology and CAPHRI Research School, Maastricht University Medical Center, Maastricht, The Netherlands.|5 Health~Holland, Topsector Life Sciences and Health, The Hague, The Netherlands.
authors.forename: Nico Lu
authors.initials: NL
authors.lastname: van Meeteren
mesh_terms: D005081:Exercise Therapy / Q000379:methods*; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D011379:Prognosis; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis / Q000534:rehabilitation*; D011788:Quality of Life; D015203:Reproducibility of Results; D055070:Resistance Training / Q000379:methods; D012720:Severity of Illness Index; D016896:Treatment Outcome
keywords: Chronic obstructive pulmonary disease; meta-analysis; physical exercise; systematic review; therapeutic validity