The influence of regular exercise on cardiac remodeling after aortic valve replacement (AVR) is virtually unknown. The case is reported of a 49-year-old male patient who had undergone biological valve replacement for severe aortic regurgitation with reduced left ventricular ejection fraction (LVEF; 45%) and massive left ventricular dilation (left ventricular end-diastolic diameter (LVEDD) 96 mm), which had been recognized for at least three years before surgery. Starting with the normal postoperative cardiac rehabilitation, the patient subsequently intensified his regular endurance training, reaching a total of 9,500 km of cycling within one year. The LVEF (51%) and LVEDD (60 mm) were almost normalized within this period. This was accompanied by an increase in peak VO2, from 27 to 52 ml/min/kg, and in peak exercise capacity (bicycle ergometer) from 75 to 283 W. These findings indicate that even intensive endurance training after AVR seems to be feasible and safe, and may have a beneficial effect on postoperative cardiac remodeling.