Effect of major school playground reconstruction on physical activity and sedentary behaviour: Camden active spaces.

Background: The physical school environment is a promising setting to increase children's physical activity although robust evidence is sparse. We examined the effects of major playground reconstruction on physical activity and sedentary time in primary schools using a quasi-experimental design (comparison group pre-test/post-test design).

Methods: Five experimental and two control schools from deprived areas of inner city London were recruited at baseline.