The objective of this study was to describe the levels and bouts of physical activity (PA) and sedentary behaviour (SB) among preschoolers in Nova Scotia, Canada, and the proportion meeting PA and step guidelines. Children (75 boys, 49 girls; mean age = 4.2 (range = 3-5 years)) participating in the Physical Literacy in the Early Years (PLEY) study provided data. Average time (minutes, % of day) spent sedentary, in light PA (LPA), moderate-to-vigorous PA (MVPA), and total PA; average frequency; and duration of bouts of MVPA (≥5 min, ≥10 min) and sedentary bouts (≥10 min) per day were determined using published cut-points, using 15-s epochs. The proportion of children meeting PA and step guidelines was determined, and differences by sex explored. Children spent the majority (70.8%) of their day active; nearly all (≥97%) met PA guidelines. Most children met step guidelines on a weekly basis, but not daily. Only LPA differed by sex (greater in girls;= 0.001). Little time was spent in sustained SB (bouts ≥10 min). Boys had greater and longer bouts of MVPA and spent more of their day in these (< 0.05). Girls spent less time in sustained SB (= 0.009). This is the first study to describe the PA and SB of Nova Scotia preschoolers using accelerometry. Findings suggest preschoolers spend the majority of their day active, and that there are sex-related differences in PA and SB, warranting further examination. p p p
