A 93-year-old man does his morning laps at the Freeport Recreation Center in Freeport, N.Y.
Posted 7/28/05
By Cory Hatch
As 33-year-old Lance Armstrong heads into retirement after his final 2,233-mile bike trek across France, the hyperfit Texan may look young, but his lungs of steel probably don't work like they used to. Recently, researchers in Baltimore found that aerobic fitness in both men and women declines faster with each passing decade, even for people who exercise.
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Researchers periodically measured the aerobic fitness of 810 healthy men and women ages 21 to 87. About once every two years, participants reported to the laboratory and ran on a treadmill until physically exhausted. The study, part of the Baltimore Longitudinal Study of Aging, is unique in that researchers followed the same individuals for as long as 20 years. While the participants ran, the scientists recorded how much oxygen they inhaled and how much carbon dioxide they exhaled. They then measured aerobic fitness by calculating each person's VO2 max, the maximum amount of oxygen used per minute. While the VO2 max declined only 3 percent to 6 percent per decade for people in their 20s and 30s, that rate increased to more than 20 percent per decade for people 70 and older, according to scientists at the National Heart, Lung, and Blood Institute and the National Institute on Aging. The study, which appeared in the online version of Circulation July 25, showed that women's aerobic fitness didn't decline quite as sharply as men's.
Unfortunately for Lance, armchair athletes showed no worse a rate of aerobic decline than those who exercised frequently.
"The picture is a lot more pessimistic than we thought," says Edward Lakatta, coauthor of the study and director of the Laboratory of Cardiovascular Science at the National Institute on Aging.
But the news for athletes isn't all bad. People who exercise regularly have an aerobic capacity that's 15 to 25 percent higher than that of their sedentary counterparts. Further, it's never too late to start. "Aerobic capacity can be increased at all ages," Lakatta explains. "Senior athletes increase their oxygen capacity by about a third. It makes them look like sedentary younger people. The heart can pump stronger and the body's tissues can extract more oxygen when you're conditioned."
Exercise can also help prevent a number of different diseases including depression, coronary artery disease, stroke, colon cancer, osteoporosis, and diabetes.
"The more you exercise, the better off you are," says independent researcher Patricia Bloom, associate professor at the Brookdale Department of Geriatrics at Mount Sinai Hospital.
Elderly people don't just benefit from running laps around the track. Other studies show that, unlike younger adults, the elderly can increase their aerobic capacity by lifting weights. Even lifting light weights can help reduce the muscle loss commonly associated with aging.
"Walking around the yard probably isn't enough," says another independent expert, Dan Bensimhon, director of the Cardiopulmonary Exercise Testing Laboratory at Duke University Medical Center. "For anybody over 50, you probably need a combination of both [cardiovascular and strength training]."
While Bensimhon says the Baltimore study is one of the best on the effects of aging, he urges caution because the study relied on participants to self-report their levels of exercise. He also doesn't want people to become discouraged.
"I don't want people to come away from this article thinking that they have to start exercising when they're 30," he says.
Xeno Muller, Olympic gold and silver medalist, indoor rowing, rowing technique.
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