Abstract
BACKGROUND: Physical fitness and body composition in preschool years are crucial for health. However, the association between them in preschool children is not yet fully understood. This research examines the link between physical fitness and body composition in Chinese children aged 3 to 6 years. METHODS: The cross-sectional study included 472 preschool children. Physical fitness was evaluated using the PREFIT battery which involves five dimensions: cardiorespiratory fitness (PREFIT 20m shuttle run), upper/lower limb strength (handgrip/standing long jump), speed-agility (4 × 10m shuttle run), and balance (one-leg stance). Body composition was determined through bioelectrical impedance analysis. RESULTS: Partial correlation analyses indicated that elevated Physical Fitness T-scores (PHT), as well as increased upper and lower limb strength, speed-agility, and cardiorespiratory fitness, correlated with reduced fat mass indices and enhanced muscle mass indices. Higher bone mineral content index is associated with improved lower-limb strength and speed-agility. There was no notable correlation between balance performance and body composition. The results also revealed that both fat and muscle mass indices are dependent on changes of physical fitness ability except for balance among preschool children. Multiple linear regression analysis also identified significant positive associations between muscle mass indices and physical fitness parameters (handgrip, standing long jump, 4 × 10m shuttle run, and PREFIT 20m shuttle run), while significant negative associations were observed between these fitness measures and fat mass indices. CONCLUSIONS: The findings indicate a significant associations between physical fitness and both fat and muscle composition in preschoolers, emphasizing the importance of physical fitness development and regular monitoring into health initiatives for this age group.