Physical Fitness Is Longitudinally Associated With Academic Performance During Childhood and Adolescence, and Waist Circumference Mediated the Relationship.

Purpose: The current investigation aimed to investigate the longitudinal association between physical fitness and academic performance over 3 years in adolescents. A secondary aim was to determine to what extent waist circumference mediated the association between physical fitness and academic performance. Methods: For the current study, 1020 students from first grade [mean age: 7.87 (0.34) y] to fifth grade [mean age: 11.87 (0.37) y] were monitored annually for 3 years (2010-2013). Physical fitness was assessed using the Andersen test, 5 x 5-m shuttle run, jump height, and grip strength tests and by constructing a composite score combining all 4 fitness tests. Academic performance was assessed by national standardized tests in Danish language and math Generalized structural equation modeling was used to evaluate the relationships between these variables. Results: The Andersen test (standardized beta = 0.15 SD), shuttle run (beta = -0.18 SD), jump height (beta = 0.10 SD), and the fitness composite score (beta = 0.23 SD) were positively associated with academic performance over 3 years. In addition, waist circumference partially mediated the association between physical fitness and academic performance. Conclusion: Thus, physical fitness abilities should be stimulated during childhood and early adolescence because of their positive association with academic performance.