An elderly person's ability to walk a quarter-mile is an important predictor of their future health and even how long they will live, new research shows.

Of the nearly 3,000 healthy people ages 70 to 79 in this multi-center U.S. study, those who were able to complete a quarter-mile walking test in good time were three times as likely to live longer and were much less likely to suffer from cardiovascular disease and physical disability as they aged.

The participants did the walking test every six months and were periodically evaluated for an average of just under five years. Those who walked the slowest had a three times greater risk of death than those in the fastest 25 percent. The slowest walkers also had a higher risk of heart disease, limited mobility, and disability.

"This shows the predictive value of a simple performance task," researcher Marco Pahor, director of the University of Florida's Institute on Aging in Gainesville, said in a prepared statement. "This will help us develop a testable standard for fitness, which is the first step toward creating a strategy for maintaining independence in older people," he said.

Pahor noted that current methods of assessing aerobic fitness, such as an exercise treadmill test, are more arduous than walking and are difficult to apply to elderly people because of age-related declines in physical abilities.

This study supports the use of the extended walking test as a baseline for fitness in seniors. The findings appear in this week's issue of the Journal of the American Medical Association.

One key to successful aging is to learn how to prevent people from becoming unable to perform common daily activities, such as walking, Pahor said.

"The most promising intervention is regular physical activity; those who do more are more likely to live longer and be healthier. This research is one step toward developing an intervention," he said.