Author(s): JIANG, S., NG, J.Y.Y., HA, A.S., Institution: THE CHINESE UNIVERSITY OF HONG KONG, Country: HONG KONG, Abstract-ID: 471

INTRODUCTION:
The 24-hour movement behaviors (24-HMB) framework integrates recommendations for physical activity (PA), sedentary behavior (SB), and sleep, which is thought to impact health and development. However, limited research has focused on gender differences in the full distribution of 24-HMB and its health-related outcomes among preschoolers. This study aimed to assess gender differences in 24-HMB and physical fitness (PF). Additionally, the study sought to examine the association between 24-HMB and indicators of PF in this population.
METHODS:
A cross-sectional study was conducted with 119 preschoolers (57 boys; 5.03 ± 0.76 years old). PA (light, moderate-to-vigorous, and total), SB, sleep duration, and screen time were measured using accelerometers and parental reports. PF components (cardiorespiratory fitness, speed-agility, lower-body muscular strength, and balance) were assessed using the PREFIT Battery. To examine the relationships between 24-HMB and PF, multiple linear regression models were employed with PF as the dependent variables and 24-HMB as the independent variables while accounting for age, body weight status (BMI), and gender as control variables. A multivariate analysis of variance was conducted, controlling for age and BMI, to investigate gender differences in 24-HMB and PF.
RESULTS:
Positive associations were found between cardiorespiratory fitness (CRF) and moderate-to-vigorous physical activity (MVPA) (β=0.254) and total PA (β=0.202), while a negative association was found between CRF and screen use time (β= -0.198). No significant correlations were observed between movement behaviors and other fitness indicators (p>0.05). The results of the multivariate test indicated a significant main effect of gender on both 24-HMB and PF (F=2.53, p<0.001). Compared to girls, boys showed significantly higher MVPA (F=3.84, p=0.012), longer sleep duration (F=4.92, p=0.003), and less screen use time (F=3.40, p=0.021). However, there are no significant gender differences were found in total PA (p=0.101) and SB (p=0.305). Furthermore, boys demonstrated significantly better balance ability (F=11.60, p<0.001), speed ability (F=10.26, p<0.001), and CRF (F=4.32, p=0.007) than girls, but no significant difference was observed in lower-body muscular strength (p=0.214).
CONCLUSION:
The study identified disparities in 24-HMB and PF between girls and boys, with boys demonstrating higher levels of PA, longer sleep duration, lower SB, and superior PF performance. Future research should take into consideration the unequal distribution of 24-HMB and PF between genders. Additionally, targeted PA interventions should be implemented to improve 24-HMB and PF specifically in girls. Furthermore, PA and screen use time appear to be effective and reliable predictors of preschoolers CRF, underscoring the importance of promoting healthy 24-HMB for PF development in young children.