Teun Remmers

General discussion | 201 120. Jago R, Page AS, Cooper AR. Friends and physical activity during the transition from primary to secondary school. Medicine & Science in Sports & Exercise. 2012;44(1):111-7. 121. De Meester F, Van Dyck D, De Bourdeaudhuij I, Deforche B, Cardon G. Changes in physical activity during the transition from primary to secondary school in Belgian children: what is the role of the school environment? BMC Public Health. 2014(14):261. 122. Richmond RC, Smith GD, Ness AR, den Hoed M, McMahon G, Timpson NJ. Assessing causality in the association between child adiposity and physical activity levels: a Mendelian randomization analysis. PLoS Medicine. 2014;11(3). 123. Aminian S, Hinckson EA. Examining the validity of the ActivPAL monitor in measuring posture and ambulatory movement in children. International Journal of Behavioral Nutrition and Physical Activity. 2012;9(1):119. 124. Ferguson T, Rowlands AV, Olds T, Maher C. The validity of consumer-level, activity monitors in healthy adults worn in free-living conditions: a cross- sectional study. International Journal of Behavioral Nutrition and Physical Activity. 2015;12(1):42. 125. Dominick GM, Winfree KN, Pohlig RT, Papas MA. Physical activity assessment between consumer-and research-grade accelerometers: a comparative study in free-living conditions. Journal of Medical Internet Research. 2016;4(3):110. 126. Tully MA, McBride C, Heron L, Hunter RF. The validation of Fitbit Zip physical activity monitor as a measure of free-living physical activity. BMC Research Notes. 2014;7(1):952.