Exercise, notably aerobic exercise like running and cycling, is good for the heart. Here are long-term benefits:
A stronger, bigger heart. With exercise, the heart increases in size, just like any other muscle. An athlete’s heart may be one-third larger than a normal heart. Muscle fibers become thicker; the chambers become larger and their walls thicker. (This is different from the type of heart enlargement resulting from disease.)
Increased cardiac efficiency. As your heart gets bigger and stronger, it’s able to pump more blood with each contraction, and thus more efficiently deliver oxygen to muscles and carry away waste products.
Lower heart rate. Since a strong heart pumps more blood with each beat, it can beat more slowly to achieve a given output of blood, both during exertion and at rest. Studies have linked lower resting heart rates with better health and longevity.
Faster recovery from the stress of exertion. Over time, the more intensely you exercise, the quicker your heart will recover from the stress.
Lower blood pressure. Aerobic exercise and even strength training, performed regularly, can help control blood pressure.
Bottom line: Add it up, and exercise enhances the entire cardiovascular system and reduces the risk of heart disease.