Mo Farah and Boris Johnson have been photographed running to launch a campaign encouraging children to be more active.

The Olympic star and London mayor visited the Lilian Baylis School in Kennington, south London.

The pair are giving their backing to a report that warns England faces an "epidemic of physical inactivity" unless the Government changes the nation's sporting infrastructure.

The Move It report, written by the Young Foundation, found that while London 2012 provided a fantastic showcase for elite British sport, fewer people are taking part in physical activity.

Only 5 per cent of adults exercise for the Government recommended two-and-a-half hours a week.