In today's weight room, you're as likely to see a grandmother working her glutes as a quarterback working his quads now that resistance exercise is recognized as vital to building strong muscles and bones.

Now the American Heart Association (AHA) says pumping iron is also good for that most important of muscles -- the heart.

In a scientific advisory, the AHA says that for healthy adults -- and some cardiac patients -- a regular program of weight training not only increases muscle strength and endurance, it also improves function of the heart and lungs, enhances glucose metabolism, reduces coronary disease risk factors and boosts well-being.

"Over the last five or six years, there's been increasing scientific evidence that resistance training offers far more than just body beautiful," says physiologist Barry A. Franklin, a co-author of the AHA advisory and director of the cardiac rehabilitation program at William Beaumont Hospital in Royal Oak, Mich. "After reviewing the literature, we came to the rather startling conclusion that resistance training, like aerobic exercise, can improve cardiovascular function and favorably modify many of the risk factors associated with coronary heart disease."

Aerobic exercise -- such as walking and jogging -- is still considered the most heart-healthy form of physical activity, states the advisory, which was published last month in the journal, Circulation. A complementary program of weight training, however, can provide such important additional benefits that the AHA urges healthy adults and many low-risk cardiac patients to do a single set of 8 to 10 different resistance exercises two or three days a week.