INTRODUCTION: This study aimed to investigate the effects of two exercise-based programs over a short-term 6-week period, compared to a control group (no exercise program), on the quality of life (QoL) and mental health of patients with myocardial infarction (MI). METHODS: In this randomized controlled trial, 72 patients with MI were individually randomized (1:1:1) into three groups: HIIT, MICT, and control. Both training programs consisted of 6 weeks of supervised treadmill exercise, three sessions per week. MICT was performed at ≈70-75% of peak heart rate (HR), while HIIT was performed at ≈85-95% of HRpeak. The control group followed standard medical recommendations. Outcome measures included assessments of QoL (SF-36) and anxiety and depression (HADS). RESULTS: In the exercise groups, 6 out of the 8 SF-36 dimensions showed a significant improvement after 6 weeks. The HIIT group exhibited noteworthy enhancements in physical functioning ( CONCLUSION: Both exercise programs were equally effective in improving QoL and mental health in MI patients. However, the HIIT group showed greater improvements in physical functioning and general health dimensions than the MICT group. Our findings emphasize that abstaining from exercise-based post-MI programs correlates with lower QoL, and higher anxiety and depression scores. This underscores the significance of implementing exercise-based rehabilitation strategies to optimize the recovery and well-being of patients with MI.