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Your circulatory system benefits the most in the early going. Practically from the moment your heart starts pounding harder, your blood vessels become more flexible, lowering blood pressure. For 18 to 24 hours after you exercise, your body becomes more sensitive to the insulin it produces, keeping your sugar levels efficiently in check and reducing your risk of diabetes. A study of more than 5,000 women with diabetes published in the Annals of Internal Medicine last month found that those who walked the most (and at a brisk pace) lowered their risk of heart disease and stroke better than 40%.
"We know that if everybody exercised a few hours a week, Type 2 diabetes would be virtually nonexistent," says Ken Goodrick, associate professor at Baylor College of Medicine in Houston. "The trick is motivating everyone to do it."
Somewhat unexpectedly, the benefits of regular exercise appear to be relatively independent of how much you weigh. A 1999 study of 25,000 men (average age: 44) showed that, all other things being equal, men who were obese and physically fit had about the same risk of death over a 10-year period as men who were both physically fit and of normal weight. By contrast, men of normal weight who were unfit were twice as likely to die as the obese but fit men. "It's pretty clear that if you follow a healthy diet and don't smoke but don't exercise, you are still at high risk [of chronic illness]," says Steve Blair, an author of the study and director for research at the Cooper Institute in Dallas. Men who were both obese and inactive faced the worst odds: they were three times as likely to die of heart disease as physically fit men of normal weight.
So get moving--even if you don't need to lose weight or have given up trying. Top choices include brisk walking, moderately fast dancing and swimming. "A lot of it comes down to trying to do more than you're already doing," says Abby King, a health researcher at Stanford. "We start people where they are and encourage them to build on that. If they jump in too quickly and get sore, they quit."
Watch Your Weight
Doctors have long known that being 30 lbs. or more overweight dramatically increases your risk of heart disease, diabetes, gallbladder disorders and arthritis. The most effective strategies for losing weight and keeping it off, according to a 1997 study of men and women who had dropped at least 30 lbs. for more than five years, consist of cutting back on caloric intake while significantly boosting physical activity. Yet only about 20% of folks who say they're trying to lose weight depend on a combination of diet and nearly daily exercise in their efforts.
Can't imagine losing 30 lbs.? Current research shows that many overweight folks who shed as few as 10 lbs. can lower their blood pressure (though it won't necessarily make it normal) and, in some cases, reduce their risk of diabetes. The goal is to drop just a pound or two a week so that the body doesn't lower its metabolic thermostat to starvation-level readings. (Paradoxically, losing weight too rapidly increases the risk of developing gallstones.) Even such a gradual regimen has recently been shown to result in the loss of muscle as well as fat, however, unless you also include a moderate strength-training routine.
Is 10 lbs. too much to ask? Then just make sure not to gain any more. Indeed, such a large proportion of the U.S. population is overweight that the American Heart Association decided last year for the first time to stress the importance for adults of trying to maintain their current weight rather than just urge the overweight to slim down. Of course, the older you get, the harder this is to do. For most folks, the solution is to combine eating moderately with exercise that strengthens both the heart and skeletal muscles.
Drink Less (if at all)
What is it about alcohol that triggers our most moralistic impulses and feeds our deepest reserves of denial? There is no question that many people can drink alcohol without suffering lasting side effects and may, in some cases, be healthier for it. There is also no question that for some folks--not all of them alcoholics--even a single drink is poison.
The evidence suggests that consuming a moderate amount of alcohol, equal to a glass or two of wine, may benefit the heart and blood vessels. But the results aren't overwhelmingly positive. Furthermore, it doesn't take much to trigger a host of ills--from fistfights to high blood pressure. A lot depends on circumstances and individual physiology. "A young healthy woman may, for example, be able to drink one or two glasses of wine a week," says Samir Zakhari, director of the division of basic research at the National Institute on Alcohol Abuse and Alcoholism. "But that's not something she should be doing if she's pregnant or trying to become pregnant."
You don't have to wait until you're 90 to get started. Studies show that some of the greatest benefits occur in men and women who pick up weight training in their 30s and 40s. That doesn't mean you can ignore aerobic activity, however. Even a brisk walk three times a week for half an hour at a stretch does some good. But the best cardiovascular results appear once you start breaking a sweat at least five days a week. As you become more fit, you may need to increase the intensity or duration of physical activity.