Researchers from Stanford University of Medicine surveyed 538 members of a nationwide running club and 423 healthy non-runners recruited as controls. All participants were older than 50 when the study began in 1984 and all were required to complete an annual questionnaire giving details of exercise frequency, body mass index, and their ability to perform activities of daily living such as walking, dressing, washing, getting out of a chair, and gripping objects. Nineteen years into the study 34% of non-runners had died compared to just 15% of runners. Disability increased along with age in both groups, however in the runners the onset of disability occurred significantly later.
As well as promoting longevity and reducing the risk of disability the study also showed that running was associated with a lower risk of death from cardiovascular disease, cancer, neurological disease, infection, and other causes. The authors attribute the benefits observed among the runners to increased cardiovascular fitness and improved aerobic capacity, greater bone mass, lower levels of inflammation, improved vaccination response, and better cognitive function.
Chakravarty EF, Hubert HB, Lingala VB, Fries JF. Reduced Disability and Mortality Among Aging Runners: A 21-Year Longitudinal Study. Arch Intern Med. 2008;168:1638-1646.
