Physical Fitness and Cognitive Performance in Preschool Children: Cross‐Sectional and Longitudinal Associations From the <scp>ELFIT</scp> Trial

Growing evidence shows that physical fitness and cognitive function might be interrelated, but evidence is mostly cross-sectional and research in preschool children remains scarce. We aimed to analyze both cross-sectional and longitudinal associations between fitness indicators and cognitive outcomes in preschoolers. In this secondary analysis of the ELFIT trial, 99 children (58 girls; mean age 4.8 ± 0.7 years) were assessed at baseline and after a 10-week intervention. Physical fitness (cardiorespiratory fitness, speed-agility, handgrip strength, and standing long jump) was measured with the PREFIT battery, whereas cognitive outcomes were assessed using selected computerized BENCI subtests. Cross-sectional analyses revealed significant associations of cardiorespiratory fitness with verbal memory, delayed verbal memory, cued recall, and verbal fluency, whereas handgrip strength was associated with free recall, and speed-agility and lower-limb strength with verbal comprehension (figures) (all pFDR < 0.05). In longitudinal analyses, improvements in cardiorespiratory fitness were significantly associated with improvements in free recall (pFDR = 0.009). Improvements in handgrip strength were associated with free recall (pFDR = 0.009), cued recall (pFDR = 0.010), verbal memory (pFDR = 0.009), delayed verbal memory (pFDR = 0.042), and delayed verbal memory recognition (pFDR = 0.011). Speed-agility was longitudinally associated with improvements in free recall (pFDR = 0.010), verbal memory (pFDR = 0.010), and verbal fluency (pFDR = 0.049). Lower-limb strength was associated with free recall (pFDR = 0.026), verbal memory (pFDR = 0.009), and verbal fluency (pFDR = 0.049). No significant associations were observed for reaction time or visuomotor outcomes after FDR correction. Overall, these findings suggest that fitness-cognition relationships in preschool children may be selective rather than generalized across cognitive domains, with the most consistent associations involving memory- and language-related outcomes.