Effects of a playground marking intervention on school recess physical activity in French children ☆ Aurélie Blaes a , Nicola D. Ridgers b , Julien Aucouturier a , Emmanuel Van Praagh c , Serge Berthoin a , Georges Baquet a, ⁎ a University of Lille Nord de France, UDSL, EA 4488 “Physical Activity, Muscle, Health”, Faculty of Sport Sciences and Physical Education, 9 Rue de l'Université, 59790 Ronchin, France b Deakin University, Centre for Physical Activity and Nutrition Research, 221 Burwood Highway, Burwood, Victoria 3125, Australia c Blaise Pascal University, EA 3533, UFR Sciences Techniques Activités Physiques et Sportives, BP 104, 63172 Aubière Cedex, France abstract article info Available online 7 August 2013 Keywords: Play Accelerometry Boys Girls Behavior Objective. Playground interventions offer an opportunity to enhance school recess physical activity. We aimed to assess the effects of playground marking on objectively measured school recess physical activity in French children. Methods. Participants were four hundred and twenty children (6–11 years old) from 4 primary schools in Nord-Pas de Calais, France. Children's physical activity (PA) was measured with a uniaxial accelerometer twice a day (morning and afternoon recess) during a 4-day school week in April and May 2009. Two experimental schools (EG) received a recess-based intervention (playground markings) and two others served as controls (CG). Percentage of time spent on the following intensities of physical activity during school recess was measured before and after intervention: sedentary (SED), light physical activity (LPA), moderate physical activity (MPA), vigorous physical activity (VPA), very high physical activity (VHPA) and moderate-to-vigorous physical activity (MVPA). Results. At baseline, school recess PA among children from CG was significantly (p b 0.001) higher than that among EG children. No interaction was observed between the recess-based intervention and gender. After the intervention, the EG spent significantly (p b 0.05) more time in MPA, VPA and MVPA with a concomitant signif- icant decrease in SED (p b 0.05) compared to baseline, while the PA in CG remained unchanged. Conclusion. Painted playground markings had a positive short-term effect on school recess physical activity levels. © 2013 Elsevier Inc. All rights reserved. Introduction Previous studies have shown that the decline in children's physical activity (PA) might start at an early age (Nyberg et al., 2009; Reilly et al., 2004). Nyberg et al. (2009) suggested a biological explanation for this decline as spontaneous overall PA decreased not only during school days but also during weekends (Blaes et al., 2011; Nyberg et al., 2009). PA is important for the metabolic health of children. The World Health Organization (WHO, 2010) recommends that children should accumulate at least 60 min of moderate-to-vigorous intensity PA daily to provide health benefits and perform a minimum of three times a week of vigorous-intensity activities including those that strengthen the musculoskeletal system; achieving 90 min of daily activity might be necessary for children to prevent insulin resistance, which seems to be the central feature for clustering of cardiovascular disease risk factors (Andersen et al., 2006). To improve children's PA levels many strategies can be imple- mented, including active commuting (Sirard et al., 2005), after-school PA programs (Trost et al., 2008), and school-based interventions (Taylor et al., 2011). Schools are an ideal setting to promote PA because most children attend school and thus can be targeted (Naylor and McKay, 2009). However, in some countries, schools are facing increas- ing pressure to improve standardized test scores in mathematics and science performance (e.g. in Europe, OECD Program for International Student Assessment, PISA report, 2009). Moreover, particularly in the US, many schools have significantly reduced the time allocated for recess, with some school districts eliminating recess completely (Lee et al., 2007). Further, PE in elementary schools has limited potential to significantly contribute to the daily PA levels of most young people (Parrish et al., 2009). Consequently, opportunities for children to engage in PA on a daily basis during the school day have declined considerably. In response to these trends, researchers and educators have started to focus on opportunities to promote PA during school playtime or Preventive Medicine 57 (2013) 580–584 ☆ Nicola Ridgers is funded by an Australian Research Council Discovery Early Career Researcher Award. ⁎ Corresponding author at: EA 4488, Faculty of Sport Sciences and Physical Education, 9 rue de l'Université, 59790 Ronchin, France. Fax: +33 320887363. E-mail address: georges.baquet@univ-lille2.fr (G. Baquet). 0091-7435/$ – see front matter © 2013 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.ypmed.2013.07.019 Contents lists available at ScienceDirect Preventive Medicine journal homepage: www.elsevier.com/locate/ypmed