Hemodynamic overload due to long-term training usually involves both left and right ventricles, inducing changes in cardiac structure such as an increase in internal cavity diameters, wall thickness and mass. Standard Doppler echocardiography has been widely used to identify the athlete's heart and to distinguish it from left ventricular pathologies. Pulsed Doppler myocardial imaging (DMI) extends Doppler applications beyond the analysis of cardiac blood flows to the measurement of myocardial wall motion. Recent reports have documented the usefulness of DMI in the evaluation of the athlete's heart. In particular, DMI analysis of trained subjects may represent a valid noninvasive tool in the following fields of application: 1) to assess differences in myocardial function in diverse forms of both physiological and pathological left ventricular hypertrophy; 2) to predict left ventricular performance during effort; 3) to analyze the effects of different training protocols on ventricular regional function; 4) to evaluate biventricular cooperation; 5) to detect myocardial dysfunction associated with pathological genotype in cardiomyopathies.