Superior Effects of High-Intensity Interval Training Compared to Conventional Therapy on Cardiovascular and Psychological Aspects in Myocardial Infarction

OBJECTIVE: To evaluate the effect of high-intensity interval training (HIIT) on psychological symptoms, activity states, and cardiovascular functions in patients with myocardial infarction (MI) of low and moderate risk stratification. METHODS: This prospective study randomly allocated 44 patients with MI to 18 sessions of HIIT or conventional moderate-intensity continuous training (MICT). Outcome measures were assessed at baseline and after 18 sessions. RESULTS: Post-exercise cardiovascular and functional states, maximal oxygen uptake (VO(2max)), metabolic equivalents (METs), 6-Minute Walking Test (6MWT), and Korean Activity Scale/Index (KASI) scores were significantly improved in the HIIT group compared to those in the MICT group after 18 exercise sessions. In particular, VO(2max) was significantly (p<0.005) improved in the HIIT group (7.58 mL/kg/min) compared to that in the MICT group (2.42 mL/kg/min). In addition, post-exercise psychological states (i.e., scores of Fatigue Severity Scale [FSS] and depression items of the Hospital Anxiety and Depression Scale [HADS_D]) were significantly improved in the HIIT group compared to those in the MICT group after 18 exercise sessions. HADS-D was improved by 1.89 in the HIIT group compared to decrement of 0.47 in the MICT group. FSS was improved by 6.38 in the HIIT group compared to decrement of 0.77 in the MICT group (p<0.005). CONCLUSION: This study demonstrates that HIIT can improve cardiac function, psychological, and activity states in low and moderate risk MI patients. Compared to conventional MICT, HIIT can improve cardiovascular functions, activity states, depression, and fatigue more effectively.