Teun Remmers

Investigating PA patterns in the transition from primary to secondary school | 153 sample ≈ 1000 children), of which 20 schools agreed. All children in their final year were invited to participate in a 7-day accelerometry and GPS monitoring protocol. One year later, all children changed schools. All Participating children were approached again at their secondary school for a follow-up measurement using the same protocol. Ethical approval for the PHASE-kids study was obtained from the research ethics committee of the Maastricht University Medical Centre (reference number 12-4-077). Figure 1: Geographical distribution of participating Primary and Secondary schools in the municipality of 's- Hertogenbosch, the Netherlands. Data were collected from April till July 2015 and from April till July 2016, with an average daily temperature of 15.12 degrees Celsius (SD=4.96) and 77% of the days with < 1.0mm of precipitation (based on registries from a local weather station). Sunset times during this time-period in the centre of the Netherlands were between 20:13 and 22:06 hours (data extracted from http://www.timeanddate.com/sun/netherlands ). Accelerometers and GPS loggers were distributed during school hours, where children received verbal and written instruction about how to wear the devices. Both devices were attached to the waist and worn at the right hip with a single elastic belt. Children were instructed to wear the devices during waking hours for 7 consecutive days, to only remove the belt during water- related activities (e.g. swimming, showering), and to recharge the GPS logger before going to sleep. In addition, children were asked to record the times and reasons why they took off the devices in a diary. After measurement, devices were collected by the research-staff