The hemodynamic load due to physical activity leads to structural and functional cardiac adaptations known as “Athlete’s heart”. We aimed to compare myocardial performance in different groups of trained athletes by means of 3D echocardiography and 3D speckle tracking echocardiography (3D-STE). 66 athletes [26 strength-trained athletes (STA) and 40 endurance athletes (ETA)] were prospectively enrolled. A control group of 40 sedentary subjects (sedentary group) was also included. All subjects underwent both standard and 3D evaluation of left ventricular (LV) function including 3D-STE. Left ventricular mass indexed for body surface area, LV end-diastolic (LV Dd) thickness of interventricular septum and posterior wall thickness mean values were significantly increased in athletes (p < 0.001, p < 0.01 and p < 0.001, respectively). LV diastolic diameter index had a significantly higher mean value in ETA in respect to sedentary group (p = 0.001). Despite a preserved mean value of LV ejection fraction (LV EF) in all the groups, subjects in STA group showed a significant reduction of strain in the longitudinal, radial and circumferential directions (p < 0.05 for all). Area strain mean value was also reduced in STA group (p < 0.01). In the overall population, an inverse relationship between longitudinal strain and LV Dd index (r = −0.260, p = 0.008), the E/A ratio (r = −0.249, p = 0.010) and the E’ velocity (r = −0.259, p = 0.009) has been identified. Sport-specific patterns of ventricular morphological and functional remodeling are present in athletes performing different kinds of training. 3D-STE is a useful and feasible echocardiographic technique for the assessment of sport-specific pattern of deformational adaptations.