LAUSR

Purpose Limited research has measured the effect of physical activity (PA) interventions on health-related quality of life (HRQoL) among pre-school-aged children. This study evaluates the effect of the Activity Begins in Childhood (ABC) cluster-randomized controlled trial designed to increase PA in the ages 3–5 years on HRQoL. Methods This was a cluster-randomized controlled trial where the intervention group included PA education delivered to daycare providers only, or daycare providers and parents. In the current study, the two PA intervention groups were combined. The comparator group received standard daycare curriculum (COM). A total of 215 children were included (PA n  = 161, COM n  = 54). Parents completed the proxy Pediatric Quality of Life Inventory Generic Core Scale (PedsQL™ 4.0) to measure HRQoL at baseline and the end of the 6-month trial. HRQoL scores were analyzed as physical, psychosocial, and total domains. Baseline and 6-months measurements were compared for PA and COM groups, and mean changes in scores (95% confidence intervals) were measured using absolute values. Results No between-group differences were observed for the physical ( p  = 0.17), psychosocial ( p  = 0.95) or total scores ( p  = 0.20). Paired comparisons showed that only the PA group improved psychosocial- (PA mean difference = 2.18 (0.20, 4.15), p  = 0.03; COM mean difference = 2.05 (− 1.03, 5.13), p  = 0.19) and total-HRQoL scores (PA mean difference = 2.83 (1.83, 3.84), p  < 0.001; COM mean difference = 0.19 (− 1.78, 2.16), p  = 0.84) after 6 months. Conclusion Although the within-PA group analysis showed an improvement in psychosocial and total HRQoL scores from baseline, no between-group differences were observed in the HRQoL over time among children aged 3–5 years.