The heart has to work a lot harder than it usually does if it has to pump blood through a arteries that are clogged up. The problem is that arteries do get clogged up in a majority of cases, and this leads to a heart attack or heart-failure.

This is exactly where a regime of physical exercises is going to come in handy. One of the ways you can counter the problem of clogged arteries is through physical exercise.  A regular session of physical workouts in known to counter the problem by reversing the incidence of clogged arteries because it makes the fat deposited along arteries burn.
 
But only physical exercise can never overcome the problem. Many athletes are found to have heart-related disorders. There is hardly anyone more physically active than an athlete like Jim Fixx. 

The latter was struck down by a cardiac-arrest while jogging in 1984. A postmortem investigation of the death gave out the finding that he had his arteries clogged up and blocked. This pointed towards the relation between heredity and health of the cardiovascular system.

All the same, experts do agree that physical exercise does make a big difference to the tendency of developing heart disorders. But you must be sure to consult a physician before taking up a regime of physical exercise. He is gong to be the best person to guide you.

You can always go for a  stress-test. This will keep a tab of your heart's health while you indulge in any aerobic exercise like walking or jogging. This is the best way to be in touch with sudden changes in blood pressure and heart-rate.