Conclusion Physical activity and sedentary time were highly varied and inconsistent between studies ; therefore , it is difficult to determine preschoolers ’ true amount of physical activity and sedentary time during childcare hours .
Despite this variability , preschoolers were noted to participate in high rates of sedentary time in this setting .
The lack of homogeneity is an important finding in and of itself as it highlights the lack of consistency in measuring , processing , and reporting paediatric physical activity data
Background Many preschoolers spend a substantial portion of their day enrolled in centre-based childcare ; the amounts of physical activity and sedentary time accumulated in this environment are critical to preschoolers ’ ability to meet movement guidelines .
The purpose of this systematic review was to provide a comprehensive overview of the objective ly assessed physical activity  and  sedentary time  of preschoolers in centre-based childcare ( registration no. CRD42016033502 ) .
An Intervention to Increase Physical Activity in Children: A Randomized Controlled Trial With 4-Year-Olds in Preschools.
INTRODUCTION A majority of preschool-aged children spend a significant portion of every weekday in a preschool or child care setting , where they typically participate in limited physical activity . This study determined if an ecologic physical activity intervention in preschools increases children 's  moderate- to vigorous-intensity physical activity ( MVPA ) . DESIGN RCT , with preschool as the unit of r and omization and analysis . Child physical activity was measured by accelerometry . Mixed model analysis of covariance with preschool as a r and om variable was used to test the effects of the intervention on physical activity in the total group and in sex-specific subgroups . Data were collected in 2008 - 2010 and analyzed in 2012 - 2014 . SETTING / PARTICIPANTS Children in 4-year-olds ' classrooms in 16 preschools , pair matched and assigned to intervention or control groups . INTERVENTION The intervention focused on increasing children 's physical activity by changing instructional practice s. Research ers trained preschool teachers to engage children in physical activity during ( 1 ) structured , teacher-led physical activity opportunities in the classroom ; ( 2 ) structured and unstructured physical activity opportunities at recess ; and ( 3 ) physical activity integrated into pre-academic lessons . Research staff encouraged teachers to adapt the intervention to their classrooms . MAIN OUTCOME MEASURES Minutes/hour of MVPA during the preschool day . RESULTS In an analytic sample of 379 children ( 188 intervention , 191 control ) , those in the intervention schools engaged in significantly more MVPA than children in control schools ( 7.4 and 6.6 minutes/hour , respectively ) . This difference remained significant after adjusting for parent education and length of the school day ( half versus full day ) . In the sex-specific analyses , the difference was significant for girls ( 6.8 vs 6.1 minutes/hour of MVPA , respectively ) but not for boys ( 7.9 vs 7.2 minutes/hour , respectively ) . CONCLUSIONS A flexible ecologic physical activity intervention that trains teachers to provide children with opportunities to be active throughout the school day increased MVPA in preschool children
Conclusion Physical activity and sedentary time were highly varied and inconsistent between studies ; therefore , it is difficult to determine preschoolers ’ true amount of physical activity and sedentary time during childcare hours .
Despite this variability , preschoolers were noted to participate in high rates of sedentary time in this setting .
The lack of homogeneity is an important finding in and of itself as it highlights the lack of consistency in measuring , processing , and reporting paediatric physical activity data
Background Many preschoolers spend a substantial portion of their day enrolled in centre-based childcare ; the amounts of physical activity and sedentary time accumulated in this environment are critical to preschoolers ’ ability to meet movement guidelines .
The purpose of this systematic review was to provide a comprehensive overview of the objective ly assessed physical activity  and  sedentary time  of preschoolers in centre-based childcare ( registration no. CRD42016033502 ) .