Owing to variations in actual in-school hours among the preschools, children must have worn the accelerometer for at least 50% of the In-School period for their data from that day to be considered valid. Children must have worn the accelerometer for at least 4 hours during the Non-School period for their data from that day to be considered valid. Valid All Day data required both valid In-School and Non-School data for that day. Days that children were absent from preschool and days on which total wear time ≥18 hours were excluded from the analyses because they do not represent typical school days. Children who had at least 3 days of valid data were included in the analyses. The average time spent in light PA, moderate-to-vigorous PA (MVPA), and total PA was expressed as minutes per hour of observation (minute/hour), using each child's wear time as the divisor to account for differences in monitoring time.