Circuit resistance training is an effective means to enhance muscle strength in older and middle aged adults: A systematic review and meta-analysis

Background: Physical exercise, particularly resistance training (RT), is proven treatment to reduce the accelerated decline in muscle strength exhibited by older adults, but its effect is hindered by low adherence rate, even under well-structured programs. Objective and data sources: We investigated the efficacy of circuit resistance training (CRT) on muscle strength, lean mass and aerobic capacity in older adults based on report in MEDLINE, EMBASE, Clini-calTrials.gov and Cochrane electronic (through 8/2016). Study eligibility criteria: middle and older aged men and/or women who followed a structured program, assigned to CRT. Study appraisal and synthesis methods: Out of 237 originally identified articles, 10 articles were included with a total of 362 patients with mean: age -64.5 +/- 7.4 years; 3 +/- 1.15 sessions/week; session duration 41.8 +/- 15.9 min. Results: Upper body strength modestly increased, by 1.14 kg (95% CI; 0.28-2.00), whereas larger increment was seen in lower body strength (11.99; 2.92-21.06). Higher program volume (>24 sessions) positively influenced upper body strength and aerobic capacity. Limitations: (1) variability in the studies' validity; (2) relatively low number of studies. Conclusion: CRT is a valid alternative to conventional RT. Its shorter duration and lower intensity relative to traditional RT, may increase adherence to training in older adults. (C) 2017 Elsevier B.V. All rights reserved.