Cramming all your recommended weekly exercise into one or two weekend sessions is enough to produce important health benefits, a study suggests.

And being active without managing 150 minutes of moderate activity a week was still enough to reduce the risk of an early death by a third. 

The findings are based on a survey of about 64,000 adults aged over 40 in England and Scotland.

Health experts said purposeful exercise was key to better health.

Researchers from Loughborough University and the University of Sydney analysed data on the time people spent doing exercise and their health over 18 years.

They found that no matter how often people exercised in a week or for how long, the health benefits were similar as long as they met the activity guidelines.

This was good news for people with a busy lifestyle who turned into "weekend warriors" in order to fit in all their recommended physical activity, they said.

Compared with those who didn't exercise at all, people who did some kind of physical activity - whether regularly or irregularly - showed a lower risk of dying from cancer and from cardiovascular disease (CVD), which can lead to heart attacks and strokes.

"Weekend warriors", who did all their exercise on one or two days of the week, were found to lower their risk of dying from CVD by 41% and cancer by 18%, compared with the inactive.

Those who exercised regularly on three or more days per week reduced their risks by 41% and 21%.

Even the "insufficiently active" lowered their risk by a significant amount - 37% and 14%, the researchers said, writing in an article published online in JAMA Internal Medicine.

For further information see www.bbc.co.uk/news/health