The study was published in the Archives of Internal Medicine. James Fries and colleagues from the University of Stanford, started the study in 1984 - at this time many experts thought that continued vigorous exercise like running may actually lead to damage in old age. But this study shows otherwise.
The participants were aged 50 and over at the start of the study, and the data gathered included how often they ran and exercised, body mass index (BMI), and disability level (using the HAQ disability index score of 0 for none through to 3 for unable to perform). The disability index assesses ability to do basic every day things like walking, dressing and grooming, getting out of a chair and gripping objects.
For those who died during the study, Fries and colleagues obtained cause of death from a national register.
Researchers found that at the start of the study the runners were leaner and less likely to smoke; at baseline they ran an average of 4 hours a week and by the end of the study an average of 76 minutes a week; in runners, the onset of any disability was later than in controls and runners were significantly less likely to become seriously disables in old age; 19 years into the study, 15% of runners and 34% of controls had died - runners lived longer; and finally the differences in disability and longevity between the runner group and the control group continued to diverge at the end of the study, as the participants approached their 80th birthday.
The conclusion is that running into middle and older age is significantly associated with reduced disability and a longer life. Not only does running seem to delay disability, but the gap between the runners and the controls gets bigger with time - even into the ninth decade. Researchers think that this is probably because runners are leaner and generally have healthier lifestyles.
