How daily-life functioning is related to physical fitness and daytime sleepiness among elementary school children

This study examined how elementary-school children's functioning in daily life, as assessed by the Questionnaire-Children with Difficulties (QCD), is related to their physical fitness and daytime sleepiness. All 493 children enrolled in elementary schools within the same city were invited to participate. A total of 307 children (152 males and 155 females) from Grades 1-6 for whom consent was received were included in the study. Data was collected on sex, grade, the New Physical Fitness Test level (Levels A to E), and daytime sleepiness (usually, sometimes, or almost never). We analyzed the associations of these variables with the QCD total score using a generalized linear mixed model. Sex (p = .024) and daytime sleepiness (p = .002) showed significant fixed effects on the QCD total score. The QCD total score was significantly higher among females and children with low levels of daytime sleepiness. However, the other variables (grade, p = .360; New Physical Fitness Test level, p = .520; grade × New Physical Fitness Test level, p = .930) did not show significant relationships. The results suggest that elementary-school children’s daily life functioning is associated with their daytime sleepiness but not with their physical fitness. They also suggest that sleep is important for elementary school children to function properly in daily life.