Effect of combined aerobic and resistance training versus aerobic training alone in individuals with coronary artery disease: a meta-analysis

Background: Resistance training (RT) has only a permissive role as an adjunct to aerobic training (AT) in cardiac rehabilitation. Design and methods: To compare the effect of AT with combined RT and AT (CT) we searched MEDLINE, Cochrane Controlled Trials Register, EMBASE, PreMedline, SPORT DISCUS, CINAHL (from the earliest date available to October 2009) for randomized controlled trials (RCTs), examining effects of CT versus AT on body composition, cardiovascular fitness (VO2peak), strength, and quality-of-life (QOL) in coronary artery disease (CAD) (excluding heart failure). Two reviewers selected studies independently. Results: Twelve studies met the study criteria (229 AT patients, 275 CT patients). Compared with AT, CT decreased percent body fat by -2.3% (WMD (weighted mean difference); 95% CI: -3.59 to -1.02), decreased trunk fat (SMD (standardized mean difference): -0.56; 95% CI: -0.96 to -0.15) and increased fat-free mass by 0.9 kg (WMD; 95% CI: 0.39 to 1.36) in three studies (n = 106). Similarly CT was associated with larger increases in lower body strength (seven studies, n = 225, SMD: 0.77; 95% CI: 0.49 to 1.04) and upper body strength (eight studies, n = 262, SMD: 1.07; 95% CI: 0.76 to 1.38). Compared to AT, CT improved peak work capacity (three studies, n = 92, SMD: 0.88; 95% CI: 0.45 to 1.31) and there was a trend for CT to increase (V) over dotO(2peak) by 0.41 ml/kg/min (nine studies, n = 399, WMD; 95% CI: -0.05 to 0.88). Qualitative analysis of QOL data favors CT. Study withdrawals were similar for AT (14.2% +/- 13.2) and CT (11.5% +/- 15.5). No serious adverse events were reported. Conclusions: CT is more effective than AT in improving body composition, strength, and some indicators of cardiovascular fitness, and does not compromise study completion or safety when compared to AT.