You want to get healthy. You know you need to exercise more. You may have even jump-started your New Year’s resolutions by joining a gym. But if you’re not ready to squeeze into shorts or a leotard and grunt through an hour of Spinning or Jazzercize or kickboxing, don’t despair. There’s growing agreement among exercise researchers that the intense physical activities offered by most health clubs is not the only–or even necessarily the best–path to better health. In fact, the best thing most of us can do, say the experts, may be to walk. Yes, walk. Not run or jog or sprint. Just walk, at a reasonably vigorous clip for half an hour or so, maybe five or six times a week. You may not feel the benefits all at once, but the evidence suggests that over the long term, a regular walking routine can do a world of preventive good, from lowering your risk of stroke, diabetes and osteoporosis to treating arthritis, high blood pressure and even depression. Walking, in fact, may be the perfect exercise. For starters, it’s one of the safest things you can do with your body. It’s much easier on the knees than running and, beyond an occasional stitch in the side, doesn’t trigger untoward side effects. “Regular physical activity is probably as close to a magic bullet as we will come in modern medicine,” says Dr. JoAnn Manson, chief of preventive medicine at Harvard’s Brigham and Women’s Hospital. “If everyone in the U.S. were to walk briskly 30 minutes a day, we could cut the incidence of many chronic diseases 30% to 40%.” If Americans want to do that, they have a long way to go. Fewer than a third of adults in the U.S. get the recommended amount of exercise each day, and 40% are almost completely sedentary. The result, as reported by the Surgeon General last month: a nation in which obesity may soon overtake cigarette smoking as the leading cause of preventable death. Part of the problem is that exercise always sounded so hard. Back in the 1970s and ’80s, when scientists conducted a series of studies on the subject, it wasn’t clear that exercise could prevent disease at all. In order to prove the point, researchers looked for the greatest effect–and found it at the top levels of performance. While the benefits of vigorous exercise are still unassailable, the initial results did not address a more basic question: Is there a lower limit to the amount of physical activity necessary to produce significant health benefits? The answer, as dozens of studies over the past five years have shown, turns out to be yes. Brisk walking provides many of the same benefits as more intense activities, like jogging or aerobics. The key seems to be in trading off intensity for duration. “If you’re doing nothing and start doing a little, you will get a little benefit,” says I-Min Lee, an exercise researcher at Harvard. “As you do more, you will see an additional benefit.” Because walking affects you in so many ways at once, it can be difficult to determine precisely why it’s good for you. But much of the evidence gathered so far is quite compelling. Some of the areas in which scientists have already identified benefits:
