The Real Fountain of Youth: Exercise

Moreover, a 21-year study by Fries and colleagues at Stanford, published in 2008, followed middle-age members of a runners club and compared them with men and women who didn't exercise. As they aged, the runners stayed spry — continuing to perform everyday activities — for 16 years longer than the other group.

Studies also strongly suggest regular exercise helps keep us sharp. A federal report concluded that while being physically active in midlife and beyond may not prevent dementia, it seems to delay its symptoms. Research has shown, too, that regular walking helps delay or even prevent the brain shrinkage that heralds the onset of dementia.

So are the new seniors, with their treadmills and weight machines, set to defy old age? Boomers, especially those who are educated and well-off, do engage in more leisure time workouts than their parents did; they also eat more fruits and vegetables, smoke considerably less, and have access to better medications to control high blood pressure and cholesterol, says Ali Mokdad, a professor of global health at the University of Washington. But Americans born into post-World War II prosperity also are the first generation to face social changes, global in scope, that promote a sedentary lifestyle and calorie-rich diet. "We work longer hours," says Mokdad. "We commute longer. We sit down to the TV and computer more than our parents did." And "we're paying for it by having higher rates of obesity."

Indeed, some experts predict obesity will be the boomers' Achilles' heel, negating their other health advantages as they age. Still, boomers can start now to eliminate many health risks by — you guessed it — exercising. "Right now, we are lousy at getting people to lose weight," Fries says. "But we can get people to start exercising and keep it up. It's a much more effective way to pursue the health policy."

Katharine Greider lives in New York and writes about health and medicine.

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