Jogging in your sixties and seventies could help slow down the ageing process, a study has found.
US researchers looked at the amount of energy expended by men and women who had stayed fit and active into their late sixties and early seventies.
Half of them went for regular runs while the other half walked for at least half an hour three times a week or more.
Those aged 69 or older who ran for exercise use about the same amount of energy when walking as a typical 20-year-old.
Associate Professor Rodger Kram of the Department of Integrative Physiology at the University of Colorado Boulder said: ‘The bottom line is that running keeps you younger, at least in terms of energy efficiency.
‘Walking for exercise has many positive health effects, like fending off heart disease, diabetes, weight gain and depression – it’s just that walking efficiency does not seem to be one of them.
‘Because we found no external biomechanical differences between the older walkers and runners, we suspect the higher efficiency of senior runners is coming from their muscle cells.’
The study included researchers from Humboldt State University and examined 15 men and 15 women with an average age of 69 who either regularly ran or walked for exercise.
The volunteers all had been either walking or running at least three times a week for a minimum of 30 minutes per workout for at least six months.
Professor Justus Ortega of Humboldt State University said: ‘What we found is that older adults who regularly participate in highly aerobic activities – running in particular – have a lower metabolic cost of walking than older, sedentary adults and also lower than seniors who regularly walk for exercise.
‘It’s been known for a long time that as people age their maximum aerobic capacity, or ‘horsepower,’ declines, and that is true for runners as well.
‘What’s new here is we found that old runners maintain their fuel economy.’
The experiment involved the participants walking on a force-measuring treadmill at three speeds – 1.6 mph, 2.8 mph, and 3.9 mph – and their oxygen consumption and carbon dioxide production were measured.