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 .
Relation of exercise to the recurrence rate of myocardial infarction in men. Ontario Exercise-Heart Collaborative Study.
The Ontario Exercise-Heart Collaborative Study was a multicenter r and omized clinical trial of high Intensity exercise for the prevention of  recurrent myocardial infa rct ion in men . The 4-year recurrence rate among 379 patients on a program of high intensity exercise  did not differ significantly from that among 354 control patients on a program of light exercise , despite the greater reduction in heart rate in the former group . The relative odds of recurrence in the high intensity group were 1.09 , with 95 % confidence limits of 0.61 and 1.96
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 .