Exercise can increase the mass of left ventricle, which is also called athletic heart. Athletic heart is most frequently encountered as a pathological manifestation of cardiovascular disease, and the early determinants of athelitic remodeling in the general population are largely unknown. We will recruit 45 men aged 18-25 years who will run 5000 meters 2/day for 3 months. caridac function is examined by ECG and echocardiogram, blood pressure, lipoprotein, heart rate, body weight, cardiac troponin will be examined prior to exercise program and 3 months after exercise.