Cardiologist can measure whether or not you have a healthy heart, or cardiovascular fitness, by doing a stress test with a standardized treadmill exercise test. Based on your age and the stage of exercise your fitness level can be determined. Your heart function can also be looked at with the use of an echocardiogram. This will show the main pumping chamber, the left ventricle and how it is contracting. A healthy left ventricle has a normal ejection fraction if it pumps at least 50% of the blood within it each heart beat. An ejection fraction less than 50% indicates left ventricular dysfunction and the lower the number the more server is the impairment. Progressive left ventricular dysfunction can eventually lead to congestive heart failure, meaning the heart muscle is no longer strong enough to provide blood flow to the tissues of the body. The need for a stress test is generally left to judgement of your physician; however, anybody with risk factors for heart disease should see their doctor to consider a stress test prior to embarking on an exercise program.