Prevalence of objectively measured sedentary behavior in early years: Systematic review and meta-analysis.

Our results suggest that young children spend a significant portion of their waking hours in sedentary behaviors. While at childcare, young children accumulated more sedentary behavior indoors than outdoors. Girls were more likely to be more sedentary than boys. No significant differences were found between weekdays and weekends, or between childcare and nonchildcare hours. There is a need for higher-quality studies with strong designs, using age and device appropriate cut-off points, to improve evidence-base and to better establish prevalence of sedentary behavior in young children.