Effect of High-Intensity Interval Versus Continuous Exercise Training on Functional Capacity and Quality of Life in Patients With Coronary Artery Disease

In Brief PURPOSE: There is strong evidence that exercise training has beneficial health effects in patients with cardiovascular disease. Most studies have focused on moderate continuous training (MCT); however, a body of evidence has begun to emerge demonstrating that high-intensity interval training (HIIT) has significantly better results in terms of morbidity and mortality. The aim of this study was to compare the effects of MCT versus HIIT on functional capacity and quality of life and to assess safety. METHODS: Seventy-two patients with ischemic heart disease were assigned to either HIIT or MCT for 8 weeks. We analyzed cardiopulmonary exercise test data, quality of life, and adverse events. RESULTS: High-intensity interval training resulted in a significantly greater increase in O2peak (4.5 ± 4.7 mL·kg−1·min−1) compared with MCT (2.5 ± 3.6 mL·kg−1·min−1) (P < .05). The aerobic threshold (VT1) increased by 21% in HIIT and 14% in MCT. Furthermore, there was a significant (P < .05) increase in the distance covered in the 6-minute walk distance test in the HIIT group (49.6 ± 6.3 m) when compared with the MCT group (29.6 ± 12.0 m). Both training protocols improved quality of life. No adverse events were reported in either of the groups. CONCLUSIONS: On the basis of the results of this study, HIIT should be considered for use in cardiac rehabilitation as it resulted in a greater increase in functional capacity compared with MCT. We also observed greater improvement in quality of life without any increase in cardiovascular risk. Interest in high-intensity interval training in cardiac rehabilitation is increasing. In this study, high-intensity interval training resulted in a greater increase in functional capacity, 6-minute walk test distance, and quality of life compared with moderate continuous training. No adverse events were reported in either group. High-intensity interval training should be considered for use in cardiac rehabilitation programs.