Running can slow the effects of aging, according to a 21-year study that showed elderly runners lead longer, healthier lives than their nonjogging peers.
Researchers from Stanford University in Palo Alto, Calif., followed 538 members of a U.S. running club and 423 healthy nonrunners starting in 1984. They found that runners ages 50 and older had less heart disease and staved off physical disability an average 16 years longers.
The study, published in the Archives of Internal Medicine, adds to previous research that has shown a link between exercise and improved health. Physical activity that makes the heart and lungs work harder may be even more crucial to well- being and longevity, researchers said.
"We've all come to know that exercise is good for you and the bottom line is it's even better than we thought," said James Fries, 69, an emeritus professor at the Stanford School of Medicine, the study's lead author and himself a runner. "If you have to pick a key thing that makes people healthier as they age, it's aerobic exercise."
The study showed that runners were less likely to die of cardiovascular disease, the leading cause of death in America, with 5.4 percent of runners and 10.2 percent of the comparison group dying from stroke or heart disease. Results for cancer-related deaths were similar, with 5.6 percent of runners and 9.7 percent of the control group succumbing to the disease.
The researchers project there will be a four-year difference in survival between the running group and the nonrunning group once all of the participants have died, Fries said.
Other studies have suggested that achieving the benefits of exercise can be a balancing act. Some researchers have cautioned that too much exercise can increase the chances of developing heart disease. James Fixx, the author of "The Complete Book of Running," who died after a training run in 1984, is often cited as an example of this danger.
In 2007, a group of researchers at the University of Maryland Medical Center in Baltimore published a report on the risks of too much exercise after a 51-year-old colleague failed a test used to determine hardening of the arteries.
The patient had jogged at least one hour a day starting at age 21 and ran two marathons every year. The running increased calcium deposits in his heart and raised his blood pressure to dangerous levels during the exercise, the report published in the March 2007 issue of the American Journal of Cardiology said.
Fries said examples of marathon runners dropping dead, such as four-time national distance-running champion Ryan Shay's death in 2004 during U.S. Olympic Team trials, overemphasize risks.
"There are hundreds of studies that associate exercise with longevity," Fries said. "Anything that would put too many barriers in front of serious exercise does people a disservice."
The Stanford researchers controlled for differences between the two groups in age, sex, smoking history, body mass index, initial disability and weekly aerobic exercise, the study said.