Running can slow the effects of aging and give older people a new lease of life, new research suggests.
Elderly joggers remained fit and active for longer than non-runners and were half as likely to die prematurely, scientists found.
They were also less likely to succumb to a range of age-related illnesses, including heart disease, cancer and neurological disorders.
The study, which spanned more than 20 years, began in 1984 when many experts feared the then-new jogging craze might do more harm than good to old folk.
There were concerns at the time that over-active pensioners might end up crippled by arthritis and orthopaedic injuries.
The US research showed the opposite. Far from being hobbled by too much exercise, people who kept themselves in shape by running turned out to have longer, healthier lives.
Professor James Fries, from the University of California at Stanford, said: "The study has a very pro-exercise message. If you had to pick one thing to make people healthier as they age, it would be aerobic exercise."
Prof Fries compared the progress of 284 members of a nationwide running club and 156 healthy, but non-running individuals.
Adjustments were made to take account of age, sex, smoking habits and Body Mass Index (BMI) which relates weight and height.
