Longitudinal changes in lifestyle behaviors and physical fitness of Japanese preschoolers during the COVID-19 pandemic: Results from a 7-year longitudinal study

Abstract The COVID-19 pandemic appears to have had a serious adverse impact on the healthy behaviors of preschoolers, in particular outdoor play. However, details of its impact are still unclear. Thus, in this study, we investigate changes in lifestyle behavior and physical fitness of Japanese preschoolers during the pandemic. We collected longitudinal data before and during the pandemic and objectively assessed changes in the physical fitness and lifestyle (outdoor playtime, screen time, and sleep) of Japanese preschoolers. Participants were 4,882 preschoolers in Hiroshima who underwent objective health and fitness assessments (25-m sprint, standing long jump, tennis ball throw); their parents answered questions on their demographics, physical activity, screen time, and sleep duration. Chi-squared test, ANOVA, and t-test were applied. The results showed a significant increase in screen time during the pandemic (p < 0.05), reduction in outdoor playtime in all preschool children (p < 0.001), and deterioration in all three fitness outcomes (running, jumping, and throwing) in all preschool children (p < 0.001). The results showed negative effects of the pandemic on children’s health and lifestyle behaviors and fitness, suggesting the need for various interventions to promote physical activity under pandemic conditions.