Teun Remmers

| 123 CHAPTER 8 Critical hours and important environments: relationships between afterschool physical activity and the built environment using GPS, GIS and accelerometers in 10-12-year-old children. This chapter will be published as: Remmers T, Thijs C, Ettema D, de Vries SI, Slingerland M, Kremers SP. Critical Hours and Important Environments: Relaitonships between after-school physical activity and the built environment using GPS, GIS and accelerometers in 10-12-year-old children.