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Inactivity 'killing as many as smoking'

18 July 2012 Last updated at 06:43 BST

A lack of exercise is now causing as many deaths as smoking across the world, a study suggests.

The report, published in the Lancet to coincide with the build-up to the Olympics, estimates that about a third of adults are not doing enough physical activity, causing 5.3m deaths a year.

That equates to about one in 10 deaths from diseases such as heart disease, diabetes and breast and colon cancer.

Fergus Walsh reports.