Isotemporal Substitution Effects of 24-hour Movement Behaviors on Executive Function in Preschool Children

Objective: This study aims to examine the relationship between 24-h movement behaviors (MBs) and executive function (EF) in preschool children. Methods: A total of 266 preschool children participated in this study. Physical activity (PA) and sedentary behavior (SB) were measured using an accelerometer (ActiGraph GT3X-BT), sleep duration was assessed using sleep logs, and EF was evaluated using the Early Years Toolbox. Compositional data analysis was employed to explore associations among the three movement behaviors. Results: (1) The relative distribution of 24-h MBs was significantly associated with inhibition, shifting, and updating (all p < 0.001), with a model explanatory power > 10%. The explanatory power was the highest for inhibition (16.3%). (2) After adjusting for other MBs, SB was negatively associated with inhibition (γ12 = –0.11, p < 0.001), shifting (γ12 = –1.45, p = 0.001), and updating (γ12 = –0.58, p = 0.004). In contrast, sleep (SP) was positively associated with shifting (γ11 = 1.60, p = 0.020). (3) When 15 min/day of SB was isotemporally substituted with SP, inhibition scores increased by 0.003, and shifting scores increased by 0.064; conversely, replacing SP with SB resulted in a significant decline. Conclusion: The relative distribution of 24-h MBs significantly predicted EF in preschool children. Among MBs, SB and SP were most strongly associated with EF. Shifting SB toward SP may effectively improve EF performance, particularly shifting ability.