How to live longer: Doing THIS could increase your life expectancy

And it need not all be done at once. The study found that provided the recommended 150-minute weekly tally of moderate physical activity was reached, people could help stave off killer conditions such as heart disease, cancer and type 2 diabetes.

Researchers said that a lower level of intensity was also likely to be a better fit for older people.

Study author Dr Barbara Jefferis of University College London said: "The results suggest 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."

Vigorous Government guidelines recommend at least 150 minutes a week of moderate to vigorous physical activity in bouts lasting 10 or more minutes, but researchers said that was not always easy for older adults to achieve.

They drew on figures from the British Regional Heart Study which involved 7,735 men aged 40-59 when it started in 1978-80.

In 2010-12, the 3,137 survivors were invited for a check-up, which included wearing an accelerometer, a gadget that tracks the volume and intensity of physical activity during waking hours for seven days.

Their health was then tracked until either their death or June 2016.

During the monitoring period of around five years, 194 died, but the accelerometer findings revealed that the total volume of physical activity was associated with a lower risk of death from any cause.

Heart disease remains the biggest killer in the UK, claiming about 165,000 lives each year.

The findings - published online by the British Journal of Sports Medicine - tally with advice given by the British Heart Foundation and Cancer Research UK, which have long stressed the importance of exercise.