Using compositional data analysis to explore accumulation of sedentary behavior, physical activity and youth health

•This study was the first to investigate whether activity intensities (sedentary behavior, light-, moderate-, and vigorous-intensity physical activity) in Australian children 7‒13 years old were accumulated in longer or shorter bouts within a 24-h composition and whether these were associated with health risk indicators.•Greater time in longer bouts of light-intensity physical activity, relative to shorter bouts, was significantly associated with greater zBMI and waist circumference.•Accumulating physical activity, particularly light-intensity physical activity, in frequent short bursts may be more beneficial for limiting adiposity in children compared to accumulating the same amount of physical activity at these intensities in longer bouts.