Interval training for patients with coronary artery disease: a systematic review

Interval training (IT) may induce physiological\ud adaptations superior to those achieved with conventional\ud moderate-intensity continuous training (MCT) in patients\ud with coronary artery disease (CAD). Our objectives were\ud (1) to systematically review studies which have prescribed\ud IT in CAD, (2) to summarize the findings of this research\ud including the safety and physiological benefits of IT, and\ud (3) to identify areas for further investigation. A systematic\ud review of the literature using computerized databases was\ud performed. The search yielded two controlled trials and\ud five randomized controlled trials (RCTs) enrolling 213\ud participants. IT prescribed in isolation or in combination\ud with resistance training was shown to induce significant\ud and clinically important physiological adaptations in cardiac\ud patients. IT was also shown to improve cardiorespiratory\ud fitness (e.g. VO2max, VO2AT), endothelial function,\ud left ventricle morphology and function (e.g. ejection fraction)\ud to a significantly greater extent when compared with\ud conventional MCT. No adverse cardiac or other lifethreatening\ud events occurred secondary to exercise participation\ud in these studies. However, these findings must be\ud interpreted with caution, as methodological limitations\ud were present in all trials reviewed. In conclusion, robustly\ud designed RCTs with thorough and standardized reporting\ud are required to determine the risk and benefits of IT in the\ud broader cardiac patient population. Further research is\ud required to determine optimal IT protocols for the use in\ud cardiac rehabilitation programmes, potentially contributing\ud to novel exercise prescription guidelines for this patient\ud population