24-Hour Movement Guideline Compliance and Physical Fitness in Uruguayan Preschoolers: The Role of Specific Behavior Combinations.

Background

The 24-hour movement paradigm emphasizes the interdependence of total physical activity, sleep, and screen time (ST). This study analyzed adherence to World Health Organization guidelines and the association of specific compliance combinations with physical fitness in preschoolers from Rivera, Uruguay.

Methods

Data from the pilot phase of the SUNRISE study in Uruguay were used. Total physical activity and sleep were measured via accelerometry; ST was parent-reported. A Composite Physical Fitness Z-Score was derived from 6 tests (PREFIT/SUNRISE). Linear regression models assessed associations between behaviors and fitness, adjusting for sex, age, and socioeconomic status.

Results

The sample comprised 135 children (mean age 3.8 [0.5] y; 50.4% boys). Only 11.9% met all guidelines; 20.0% met none. A higher Total Compliance Score (representing the total number of guidelines met, ranging from 0 to 3) was linearly associated with better fitness (β = 0.106; 95% CI, 0.012 to 0.200). Regarding specific compliance combinations, meeting total physical activity + ST guidelines showed a strong association with fitness (β = 0.507; 95% CI, 0.054 to 0.959), exhibiting a stronger association than meeting all 3 guidelines, which was only marginally significant. Compliance with the ST guideline was the only individual predictor independently associated with fitness.

Conclusions

Guideline compliance is low in this population. High physical activity combined with limited ST was strongly associated with optimal physical fitness, suggesting that the "move more, sit less" synergy is highly relevant for motor competence, independent of sleep duration. Consequently, interventions should prioritize protecting active play from digital displacement.