Interestingly, they found that the greatest growth in participation also occurs among seniors, reflecting an aging population that is at least somewhat concerned over maintaining a healthy lifestyle. Even marathons are no longer off limits.
"Twenty five years ago, few 60-year-old men, much less women, or their doctors would have considered it possible for someone of their age to run 26 miles," the researchers say. Not only do older runners participate, they do quite well.
"The most impressive improvements occur in the age groups 60-69 and 70-79 for men and 50-59 and 60-69 for women," the study says.
Women, especially, have embraced the concept that vigorous exercise can be especially helpful.
During the study period there were no restrictions based on sex or age on entering the New York marathon, and the numbers grew from 14,546 in 1983 to 31,791 in 1999, an increase of 119 percent.
The ratio of males to females was 5.6 to 1 in 1983. But by 1999, the ratio had dropped to 2.47 to 1.
If that trend continues, the researchers say, the ratio should be about 1 to 1 in 2007.
And the fact that each year older runners do better than the year before shows just how important regular exercise can be. There isn't any single thing we can do for ourselves that is more likely to slow the aging process, the researchers argue.
Regular exercise can lower cholesterol, the leading cause of heart disease, and "master athletes tend to be less depressed, angry and fatigued than their non-athletic counterparts," the study says.
"Many of the changes in health status previously thought to be a consequence of normal aging have been shown to be a result of sedentary lifestyle," it adds.
We've heard that all before, but apparently many people aren't listening, and the wrong numbers keep going up.
The American Hearth Association says that as of last year, 51 percent of men and 48 percent of women aged 55-64 have cardiovascular disease. And that number jumps to 65 percent for both genders aged 65-74.
"Aging is further associated with decreased muscular strength and endurance leading to a declining functional capacity and quality of life," the study says, and then it adds:
"The most dramatic aspect of this decline is probably not the result of aging but the inactivity associated with aging. Regular physical activity can reduce the risk of all causes of mortality by about 25 percent and increase life expectancy by up to two years. Despite the benefits of exercise, only 20 to 30 percent of all adults engage in vigorous activity on a regular basis, and a staggering 25 percent are totally inactive."
That's especially troubling to the researchers, who conclude that modern medicine has made it possible for us to live many years longer, but how well we live is largely up to us.
"The multifactor health benefits of exercise have been made clear, and the myth that older people cannot complete marathons has been dispelled," they conclude.
But of course, not everybody can, or should, run marathons. Numerous studies show that just a little exercise on a regular basis can make a significant difference. And it's a funny thing, but sometimes a little exercise tends to feed on itself, and pretty soon it's a lot more than a few minutes per day.
So call off the search, Ponce de Leon. We've found it.
Lee Dye’s column appears weekly on ABCNEWS.com. A former science writer for the Los Angeles Times, he now lives in Juneau, Alaska.