Relationship between actigraphy‐derived physical activity, sedentary behaviours and sleep parameters in preschool girls and boys: A cross‐sectional study.

Summary The aim of the study was to examine associations between moderate‐to‐vigorous physical activity and sedentary time with sleep quality and quantity among preschool girls and boys using objective methods. Children (5–6 years old) attending kindergarten were recruited (n = 676). Measures included accelerometer‐derived 24‐hr activity and sleep for seven consecutive days. Longer time spent in moderate‐to‐vigorous physical activity was associated with higher sleep efficiency both in boys (p < 0.0001) and girls (p = 0447), and with lower Sleep Fragmentation Index in boys (p = 0.0042) and girls (p = 0.0494). Moreover, among boys, moderate‐to‐vigorous physical activity was inversely associated with wakefulness after sleep onset (p = 0.0006), number of awakenings (p = 0.0081) and Fragmentation Index (p = 0.0041), while in girls with sleep duration (p = 0.0405), Movement Index (p = 0.0128) and Sleep Fragmentation Index (p = 0.0494). Longer time spent sedentary was associated with lower sleep efficiency, and higher wakefulness after sleep onset, number of awakenings, Movement Index and Sleep Fragmentation Index—all with p < 0.0001. Furthermore, sedentary time was inversely associated with sleep duration both in boys (p < 0.0001) and girls (p = 0.0006), and directly associated with Fragmentation Index but only in boys (p = 0.0069). Meeting the recommended level of moderate‐to‐vigorous physical activity was associated with better sleep efficiency, lower wakefulness after sleep onset and number of awakenings among boys. All sleep‐related variables showed significant differences between quartile groups according to sedentary time (p < 0.05) in both the total group and the boys. The sedentary time had the strongest, negative effect on sleep‐related parameters in preschool children, therefore sedentary time reduction may contribute more to improving sleep quality than increasing moderate‐to‐vigorous physical activity. [ABSTRACT FROM AUTHOR]