BACKGROUND: Physical exercise adds benefits improving evolution of the ischemic heart disease, enhancing individual functional capacity and preventing ventricular remodeling. In this study we investigated the impact of a program of physical training started after an uncomplicated post-acute myocardial infarction (AMI) on the mechanics of left ventricle (LV) contraction. METHODS: A total of 53 patients were included, 27 of whom were randomized to a supervised training program (TRAINING group), and 26 to a CONTROL group, who received usual orientations for physical exercise after AMI. All patients underwent cardiopulmonary stress testing and an echocardiogram with speckle tracking technique to measure several parameters of LV contraction mechanics at 1 month and 5 months after AMI. RESULTS: No significant difference in the analysis of LV longitudinal, radial and circumferential strain parameters between groups after the training period was found. After the training program, analysis of torsional mechanics demonstrated a reduction in the LV basal rotation of the TRAINING group in comparison to the CONTROL group (TRAINING, -5.9±2.3 vs CONTROL, -7.5±2.9 ^o; P=0.03), and in the basal rotational velocity ​​( TRAINING, -53.6±18.4 vs CONTROL, -68.8±22.1 º/s; P=0.01), twist velocity (TRAINING, 127.4±32.2 vs CONTROL, 149.9±35.9 vs º/s; P=0.02) and torsion (TRAINING, 2.4±0.4 vs CONTROL, 2.8±0.8 vs º/cm; P=0.02). CONCLUSIONS: Physical activity did not cause a significant improvement in LV longitudinal, radial and circumferential deformation parameters. However, the exercise had a significant impact on the LV torsional mechanics, composed particularly of a reduction in basal rotation, twist velocity, torsion and torsional velocity which can be interpreted as a ventricular “torsion reserve” in this population.