Objective.: The aim of the study was to investigate the impact of a playground redesign intervention across time on children's recess physical activity levels using combined physical activity measures and to evaluate the potential influence of covariates on the intervention effect. Method.: Fifteen schools located in areas of high deprivation in one large city in England each received £20,000 through a national £10 million Sporting Playgrounds Initiative to redesign the playground environment based on a multicolored zonal design. Eleven schools served as matched socioeconomic controls. Physical activity levels during recess were quantified using heart rate telemetry and accelerometry at baseline, 6 weeks and 6 months following the playground redesign intervention. Data were collected between July 2003 and January 2005 and analyzed using multilevel modeling. Results.: Statistically significant intervention effects were found across time for moderate-to-vigorous and vigorous physical activity assessed using both heart rate and accelerometry. Conclusions.: The results suggest that a playground redesign, which utilizes multicolor playground markings and physical structures, is a suitable stimulus for increasing children's school recess physical activity levels. © 2007 Elsevier Inc. All rights reserved.