Exercise therapy for functional capacity in chronic diseases: an overview of meta-analyses of randomised controlled trials.

OBJECTIVE To summarise all meta-analyses of randomised controlled trials that have evaluated the effects of exercise therapy on functional capacity in patients with chronic diseases. DESIGN Umbrella review of meta-analyses of randomised controlled trials. DATA SOURCES We systematically searched the CENTRAL, CINAHL, DARE, Medline, OTSeeker, PEDro, SPORTDiscus, ProQuest Nursing & Allied Health Database, Web of Science, Scopus, OpenGrey and BMC Proceedings from database inception to 1 September 2016. ELIGIBILITY CRITERIA FOR SELECTING STUDIES We included meta-analyses that compared the effects of exercise therapy with no treatment or usual care in adults with non-communicable chronic diseases and included outcomes related to functional capacity. We excluded meta-analyses with less than 100 patients. RESULTS Eighty-five meta-analyses with 22 different chronic diseases were included. The exercise interventions resulted in statistically significant (p<0.05) improvements for 126 of 146 (86%) functional capacity outcomes, compared with the control group. The standardised mean differences were small in 64 (44%), moderate in 54 (37%) and large in 28 (19%) of the 146 functional capacity outcomes. The results were similar for aerobic exercise, resistance training, and aerobic and resistance training combined. There were no significant differences in serious adverse effects between the intervention and control groups in any of the meta-analyses. CONCLUSION Exercise therapy appears to be a safe way to improve functional capacity and reduce disability in individuals with chronic disease.