Comparison of the Effects of Two Exercise Programs of High-intensity Interval Training and Moderate-intensity Continuous Training on Physiological Function of Heart Patients after Coronary Artery Bypass Graft Surgery

Abstract

Background: Exercise-based cardiac rehabilitation(CR) programs increase physiological function. However, it’s not yet clear which feature of exercise is most effective in improving important physiological performance indicators in heart patients. Therefore, the aim of this study was to compare the effects of high-intensity interval training(HIT) and moderate-intensity continuous training(MCT) on metabolic equivalent of tasks(METs), submaximal myocardial oxygen consumption(MVO2submax), and heart rate recovery(HRR) of heart patients after coronary artery bypass graft(CABG) surgery. Methods: Twenty-four post-CABG patients (15 males and 9 females) with a mean age of 60.75±3.16 years and a mean body mass index (BMI) of 28.40±1.09 kg/m2 were randomly divided into three groups of HIT, MCT and control group (CG). The training groups (HIT and MCT) trained for eight-weeks, three-sessions per week, and 45minutes per session. The research variables (METs, MVO2submax and HRR) were measured and compared in two stages before and after eight-weeks of CR programs. Results: After eight-weeks of CR programs, patients in both training groups showed a significant improvement in METs, MVO2submax and HRR (P<0.05), and the HIT group showed significantly greater improvement in METs (P=0.001) and HRR (P=0.001) compared to the MCT group, as well the MCT group showed a significantly more improvement in MVO2submax (P=0.001) than the HIT group. Also, no cardiovascular adverse events related to HIT or MCT occurred during the implementation of the study. Conclusion: According to the results of the present study, HIT seems to be more effective than MCT in improving METs and HRR of post-CABG patients, and is safe as well.