The purpose of this study was to determine the effect of 1-year lifestyle intervention (exercise and general dietary management) on myocardial dysfunction in type 2 diabetic patients (n=223). Overall, the 1-year exercise (gym followed by home-based exercise training) intervention failed to improve myocardial function in all patients despite improved waist circumference, body fat, glycaemic control, insulin sensitivity and cardiorespiratory fitness. However, results showed that subgroups of patients who had the greatest increases in both moderate and vigorous activity significantly improved myocardial tissue velocity (p<0.01), HbA1c (p=0.03) and cardiorespiratory fitness (p=0.03). Thus, these results suggest that the proposed exercise training program was not sufficient to reverse myocardial dysfunction in these patients. Thus, exercise recommendations for patients with type 2 diabetes may not be sufficient and should include both moderate and vigorous exercise.