Objectively measured physical activity level and sedentary behavior in Norwegian children during a week in preschool

•MVPA per day ranged from 16 min to 116 min in the least and most active child.•Sedentary time ranged from 2.7 h to 6.5 h per day in the least and most sedentary child.•The 25% least physically active children were less active throughout the entire day.•The 25% least active children were not more active outside than inside.•PA pattern among inactive children described in this study may inform interventions.

Although many studies have reported on physical activity (PA) levels using accelerometers, a thorough description of the PA pattern in preschool children during their stay in the preschool, is lacking in the current literature. Furthermore, there remains a lack of understanding of the PA level and pattern in children in the lower end of the PA continuum.The first aim of this study was therefore to describe the PA pattern during a week-long stay in a preschool in all children born in 2011 (either three or four-year-olds) attending public preschools in a municipality in Norway. The second aim was to describe the PA level and pattern of the children who are the least physically active.This cross-sectional study included baseline data from 95% of children (N = 111) participating in a randomized controlled physical activity intervention (Active Kindergarten - Active Children study). The participants wore an Actigraph accelerometer, in week 39 in 2015, from when they arrived at the preschool on Monday morning and throughout their stay of five consecutive days.The amount of moderate- to vigorous-intensity PA (MVPA) per day ranged from 16 min to 116 min, and sedentary time ranged from 2.7 h to 6.5 h per day in the least and most sedentary child, respectively. The least physically active 25% of children were less active throughout the entire day, and only a few of them managed to achieve the recommended level of MVPA on any weekday.The physical activity levels and patterns among the least active children described in this study may help to inform interventions targeting this group.