A little bit of leakage is completely normal for 3 of the 4 heart valves the mitral, tricuspid, and pulmonic valves. In fact, for the mitral and tricuspid valves, the backflow of blood happens well before the valve closes.
Modern echocardiography equipment is very sensitive. Almost everyones echocardiogram shows some leakage of the mitral and tricuspid valves. So, if you have a little mitral and tricuspid valve leakage, but your doctor says you dont need to worry about it, exercise as normal.
In contrast, the aortic valve doesnt normally leak not even a little. It acts like a door between the heart and the main artery of the body (the aorta). Nature probably designed this valve to close early before blood can rush back toward the heart as a way to direct blood into the coronary arteries. These arteries, which nourish the heart muscle, branch of the aorta just beyond the aortic valve. If the valve closes early, more blood pressure is available to fill the needy coronary arteries.
Exercise may be a problem when some valve diseases get severe. Thats especially true for aortic valve disease. But for mild or normal valve leakiness, there is no reason to limit your exercise.
Your valves would need to be repaired if your valve leakage became severe enough to cause symptoms or the size or shape of your heart changes. Work closely with your doctor to determine the best time to do this.