WASHINGTON - People who want to live a long and healthy life might want to take up running.

A study published on Monday shows middle-aged members of a runner's club were half as likely to die over a 20-year period as people who did not run.

Running reduced the risk not only of heart disease, but of cancer and neurological diseases such as Alzheimer's, researchers at Stanford University in California found.

"At 19 years, 15 percent of runners had died compared with 34 percent of controls," Dr. Eliza Chakravarty and colleagues wrote in the Archives of Internal Medicine.

Any type of vigorous exercise will likely do the trick, said Stanford's Dr. James Fries, who worked on the study.

"Both common sense and background science support the idea that there is nothing magical about running per se," Fries said in a telephone interview. "It is the regular physical vigorous activity that is important."

The team surveyed 284 members of a nationwide running club and 156 similar, healthy people as controls. They all came from the university's faculty and staff and had similar social and economic backgrounds, and all were 50 or older.

Starting in 1984, each volunteer filled out an annual survey on exercise frequency, weight and disability for eight ac tivities — rising, dressing and grooming, hygiene, eating, walking, reach, hand grip and routine physical activities.

Everyone exercised, but runners did more

Most of the volunteers did some exercise, but runners exercised as much as 200 minutes a week, compared to 20 minutes for the non-runners.

At the beginning, the runners were leaner and less likely to smoke compared with the controls. And they exercised more over the whole study period in general.

"Over time, all groups decreased running activity, but the runners groups continued to accumulate more minutes per week of vigorous activity of all kinds," the researchers wrote.

"Members of the running groups had significantly lower mean disability levels at all time points," they added.

The team also set out to answer whether taking up running late in life would benefit, and whether people who stopped exercising began to pay a price as they aged.

Most of the runners have stopped running as they reached their 70s, Fries said. But it was difficult to find people who totally stopped exercising. "Almost all of them did something else. They continued their vigorous exercise," he said.

People who took up exercise when they were older also improved their health, he said.

The study also showed that people cannot use the risk of injury as an excuse not to run — the runners had fewer injuries of all kinds, including to their knees.