Any exercise, but especially aerobic exercise like running, biking, or using cardio equipment at the gym, is good for your heart. How? Well, like any muscle, if you use it, your heart will increase in size, with stronger muscle fibers, and it will also pump blood more efficiently. Regular exercisers usually have lower heart rates, which increases longevity as well as a faster recovery from exertion. Exercise also promotes lower blood pressure. So any way you pump it up, your heart will pump it up, too!