Just a few minutes of light exercise - such as gentle gardening or taking the dog for a walk - helps older men live longer, according to a new study.
Researchers found that clocking up just half an hour of any level of physical activity, including of light intensity, is linked to a 17 per cent reduction in the risk of death in older men.
The study, published online by the British Journal of Sports Medicine, suggests that, providing the recommended 150 minute weekly tally of moderate to physical activity is reached, total volume, rather than activity in 10 minute bouts, as current guidelines recommend, might be key.
Researchers say that a lower level of intensity is also likely to be a better fit for older men, most of whose daily physical activity is of light intensity.
Current exercise guidelines recommend accumulating at least 150 minutes a week of moderate to vigorous physical activity in bouts lasting 10 or more minutes.
But researchers say that such a pattern is not always easy for older adults to achieve.
To find out if other patterns of activity might still contribute to lowering the risk of death, the researchers drew on figures from the British Regional Heart Study.
The study involved 7,735 participants from 24 towns in Britain, who were aged between 40 and 59 when the study stated in 1978-80.
In 2010-12, the 3,137 survivors were invited for a check-up, which included a physical examination, and questions about their lifestyle, sleeping patterns, and whether they had ever been diagnosed with heart disease.
They were also asked to wear an accelerometer- a portable gadget that continuously tracks the volume and intensity of physical activity - during waking hours for seven days. Their health was then tracked until death or June 2016, whichever came first.
In all, 1,566 (50 per cent) agreed to wear the device, but after excluding those with pre-existing heart disease and those who hadn't worn their accelerometer enough during the seven days, the final analysis was based on 1,181 men, with an average age of 78.
During the monitoring period, which averaged around five years, 194 of the men died.
The accelerometer findings indicated that total volume of physical activity, from light intensity upwards, was associated with a lower risk of death from any cause.
Each additional 30 minutes a day of light intensity activity - such as gentle gardening or taking the dog for a walk - was associated with a 17 per cent reduction in the risk of death.
The researchers said that the association persisted even after taking account of potentially influential lifestyle factors, such as time spent sitting down.
While the equivalent reduction in the risk of death was around 33 per cent for each additional 30 minutes of moderate to vigorous intensity physical activity a day, the findings show that the benefits of light intensity activity were large enough to mean that this too might prolong life.
And there was no evidence to suggest that clocking up moderate to vigorous activity in bouts of 10 minutes or more was better than accumulating it in shorter bouts.
Sporadic bouts of activity were associated with a 41 per cent lower risk of death; bouts lasting 10 or more minutes were associated with a 42 per cent lower risk.
Sporadic bouts seemed easier to achieve as two-thirds of the men (66 per cent) achieved their weekly total of moderate to vigorous physical activity in that way while only 16 per cent managed to do so in bouts of 10 or more minutes.
There was no evidence to suggest that breaking up sitting time was associated with a lower risk of death, according to the findings.
The researchers said it was an observational study so no firm conclusions can be drawn about cause and effect.
And those who wore the accelerometer tended to be younger and have healthier lifestyles than those who didn't, so it might have skewed the results.
But the researchers say the results could be used to refine current physical activity guidelines and make them more achievable for older adults.
Study author Dr Barbara Jefferis, of University College London, said: "The results suggest that all activities, however modest, are beneficial.
"The finding that low intensity physical activity is associated with lower risk of mortality is especially important among older men, as most of their daily physical activity is of light intensity."
She added: "Furthermore, the pattern of accumulation of physical activity did not appear to alter the associations with mortality, suggesting that it would be beneficial to encourage older men to be active irrespective of bouts."
Dr Jefferis said future guidance might emphasise that all physical activity, however modest, is worthwhile for extending lifespan - something that is particularly important to recognise, given how physical activity levels tail off rapidly as people age.