Vascular-endothelial adaptations following low and high volumes of high-intensity interval training in patients after myocardial infarction

Background: Determinants of coronary artery disease, such as endothelial dysfunction and oxidative stress, could be attenuated by high-intensity aerobic interval exercise training (HIIT). However, the volume of this type of training is not well established. Objective: To assess the impact of two volumes of HIIT, low (LV-HIIT, 10 min at high intensity), on vascular-endothelial function in individuals after an acute myocardial infarction (AMI). Materials and methods: Clinical trial in 80 AMI patients (58.4 ± 8.3 years, 82.5% men) with three study groups: LV-HIIT (n = 28) and HV-HIIT (n = 28) with two sessions per week for 16 weeks and control group (CG, n = 24) with unsupervised physical activity recommendations. Endothelial function (brachial flow-mediated dilation, FMD), atherosclerosis (carotid intima-media thickness ultrasound, cIMT), and levels of oxidized low-density lipoprotein (ox-LDL) as a marker of oxidative stress were determined before and after the intervention period. Results: After the intervention, in the exercise groups, there was an increase in FMD (LV-HIIT, ↑58.8%; HV-HIIT, ↑94.1%; p