Conclusions Exercise-based cardiac rehabilitation is effective at reducing important clinical outcomes in patients with coronary heart disease .
While our analysis was constrained by the quality of included trials and missing information about intervention components , there appears to be little differential effect of variations in exercise intervention , particularly on mortality outcomes .
Background While the clinical benefits of exercise-based cardiac rehabilitation are well established , there is extensive variation in the interventions used within these trials .
It is unknown whether variations in individual components of these exercise interventions provide different relative contributions to overall clinical outcomes .
This study aims to systematic ally examine the relationship between individual components of the exercise intervention in cardiac rehabilitation ( such as intensity and frequency ) and clinical outcomes for people with coronary heart disease .
Exercise duration as a determinant of vascular function and antioxidant balance in patients with coronary artery disease
Background Exercise improves the clinical outcome of patients with coronary artery disease ( CAD ) ; however , the ideal exercise duration for each patient remains unclear . Objective To investigate the effects of exercise duration on arterial elastic properties and antioxidant/pro-oxidant mechanisms in patients with CAD . Design , setting , patients , interventions Sixty male patients with CAD were r and omised into two groups , and underwent exercise for 30 min or 60 min in a crossover design with 2 weeks ' wash-out period . In all participants aortic and radial blood pressures ( BP ) and arterial elastic properties ( augmentation index (AIx)/pulse wave velocity ( PWV ) ) were determined at baseline and 24 h after exercise .  Plasma malonyldialdehyde ( MDA ) and superoxide dismutase (SOD)1 and SOD2 levels were also measured . Results Exercise had no effect on aortic and radial BP ( p = NS for all ) . Walking for 30min improved AIx ( from 33.79±0.91 % to 31.73±0.86 % , p<0.001 ) and PWV ( from 9.26±0.95 m/s to 9.06± 0.21 m/s , p<0.001 ) , while exercise for 60min had adverse effects on vascular stiffness ( for AIx : from 33.37± 0.93 % to 33.73± 1.05 % , p = NS and for PWV : from 9.25±0.19 m/s to 9.37±0.21 m/s , p<0.05 mainly in older patients ) . Exercise for 60min was associated with a significant 20 % increase in MDA levels ( p<0.05 ) . Exercise had no effects on SOD1 levels , however it significantly increased SOD2 levels after 30min ( from 2.26±0.22ng/mL to 2.36±0.18ng/mL , p<0.05 ) but not after 60min ( p = NS ) . Conclusion Shorter exercise duration was associated with favourable antioxidant and vascular effects , while longer exercise blunted these beneficial effects and was accompanied by adverse effects on vascular function , mainly in older coronary patients . Further studies are required to explore the hypothesis that a more individualised approach to the selection of the appropriate exercise programme should be considered for patients with CAD
Conclusions Exercise-based cardiac rehabilitation is effective at reducing important clinical outcomes in patients with coronary heart disease .
While our analysis was constrained by the quality of included trials and missing information about intervention components , there appears to be little differential effect of variations in exercise intervention , particularly on mortality outcomes .
Background While the clinical benefits of exercise-based cardiac rehabilitation are well established , there is extensive variation in the interventions used within these trials .
It is unknown whether variations in individual components of these exercise interventions provide different relative contributions to overall clinical outcomes .
This study aims to systematic ally examine the relationship between individual components of the exercise intervention in cardiac rehabilitation ( such as intensity and frequency ) and clinical outcomes for people with coronary heart disease .