Thirty minutes of physical activity--irrespective of its intensity--6 days a week is linked to a 40% lower risk of death from any cause among elderly men, finds research published online in the British Journal of Sports Medicine.
Boosting physical activity levels in this age group seems to be as good for health as giving up smoking, the findings suggest.
The researchers base their findings on people taking part in the Oslo Study, which invited almost 26,000 men born between 1923 and 1932 for a health check in 1972-3 (Oslo I).
Some 15,000 agreed. Their height, weight, cholesterol and blood pressure were all assessed, and they were asked whether they smoked.
They were also asked to respond to a validated survey (Gothenburg questionnaire) on their weekly leisure time physical activity levels.
These were categorised as sedentary (watching TV/reading); light (walking or cycling, including to and from work for at least 4 hours a week); moderate (formal exercise, sporting activities, heavy gardening for at least 4 hours a week); and vigorous (hard training or competitive sports several times a week).
Some 6000 of the surviving men repeated the process in 2000 (Oslo II) and were monitored for almost 12 years to see if physical activity level over time was associated with a lowered risk of death from cardiovascular disease, or any cause, and if its impact were equivalent to quitting smoking.
During the monitoring period, 2154 out of the 5738 men who had gone through both health checks died.
The analysis indicated that less than an hour a week of light physical activity was not associated with any meaningful reduction in risk of death from any cause. But more than an hour was linked to a 32% to 56% lower risk.
Less than an hour of vigorous physical activity, on the other hand, was linked to a reduction in risk of between 23% and 37% for cardiovascular disease and death from any cause.
The more time spent doing vigorous exercise the lower the risk seemed to be, falling by between 36% and 49%.
And men who regularly engaged in moderate to vigorous physical activity during their leisure time lived five years longer, on average, than those who were classified as sedentary.
Factoring in that the risk of death from heart disease/stroke rises with age, made only a slight difference to the results.
Overall, these showed that 30 minutes of physical activity--of light or vigorous intensity--6 days a week was associated with a 40% lower risk of death from any cause.
The impact would seem to be as good for health as quitting smoking among this age group, suggest the researchers.
This is an observational study so no definitive conclusions can be drawn about cause and effect, and the researchers point out that only the healthiest participants in the first wave of the study took part in the second wave, which may have lowered overall absolute risk.
But the differences in risk of death between those who were inactive and active were striking, even at the age of 73, they suggest.
More effort should go into encouraging elderly men to become more physically active, with doctors emphasising the wide range of ill health that could be warded off as a result, conclude the researchers.