What's So Great About Cardio?

How Much Cardio You Need

As a woman swims laps at the community pool or pedals her bike on a nature trail, all sorts of things are happening in her body to help keep cardiovascular disease at bay. "If done regularly, cardiovascular exercise helps improve numerous risk factors for heart disease," Dr. Goldberg says. It improves cholesterol by raising HDL cholesterol (the healthy type of cholesterol) and lowering LDL cholesterol (the unhealthy type of cholesterol). Exercise also lowers blood pressure and maintains weight loss and makes the heart stronger and more efficient so it can deliver more blood to the muscles with each beat.

The benefits of cardiovascular fitness are particularly strong in terms of keeping blood pressure down. The American Society of Hypertension recently reported that an aerobic exercise program may be the single most effective way to control blood pressure.

These benefits start to show up fairly quickly. "If you exercise for three to four weeks regularly, your blood pressure should start to go down," Dr. Goldberg says.

And although still significant, the cholesterol-lowering effects may take a little longer. "Some studies have shown that in order to get a really significant jump in HDL, a middle-aged woman may have to exercise for a year," Dr. Goldberg says.

Any physical activity is better than none, according to the American Heart Association (AHA). Even low-intensity activity -- everything from light to moderate housework, gardening, and climbing stairs -- for 30 minutes a day can help. But, more vigorous activity -- jogging, jumping rope, brisk walking, swimming -- for at least 30 minutes on most and preferably all days of the week are the best for achieving fitness for your heart and lungs.

If you've never exercised before, don't attempt to run for 30 minutes on your first day out. Too much too soon can lead to injury and burnout. After checking with your healthcare professional, start with five minutes of cardiovascular exercise every other day and build up to 30.

"Your workout shouldn't be painful" to be good for your heart, says Dr. Goldberg. "It should make you feel better," says Dr. Goldberg.