Live longer by walking, not sitting
Trading just two minutes of sitting for walking can help you live longer, scientists claim.
Getting motivated for that much time of every hour otherwise spent languishing on a sofa or remaining stuck behind a desk reduced the risk of dying by a third, a study found.
For people with chronic kidney disease, the swap was even more effective, lowering mortality by 41%.
Scientists used statistical techniques to examine the effect of "trading off" sedentary behaviour for different levels of activity.
Standing instead of sitting for two minutes every hour produced no benefit. But trading sitting time for "light activity", such as casual walking or housework, had a significant impact.
Lead scientist Professor Srinivasan Beddhu, from the University of Utah in the US, said: "It was fascinating to see the results because the current national focus is on moderate or vigorous activity. To see that light activity had an association with lower mortality is intriguing.
"Based on these results we would recommend adding two minutes of walking each hour in combination with normal activities, which should include 2.5 hours of moderate exercise each week."
Moderate exercise strengthened the heart, muscles and bones and conferred health benefits that cannot be obtained by walking alone, he explained.
The researchers analysed data from 3,243 participants in a US health and lifestyle study, the National Health and Nutrition Examination Survey, who wore movement-sensing devices to measure their activity levels.
A total of 137 deaths were recorded in the three years after the data was collected.
Co-author Dr Tom Greene, also from the University of Utah, said: "Exercise is great, but the reality is that the practical amount of vigorous exercise that can be achieved is limited. Our study suggests that even small changes can have a big impact."
The findings are published in the Clinical Journal of the American Society of Nephrology.