A121: Mediating Effects of Physical Fitness Index Between PhysicalActivity and Executive Function in Chinese Adolescents

<bold>Objective:</bold> To explore the mediating effect of physical fitness index between physical activity and executive function in Chinese adolescents, and to provide some theoretical basis for improving adolescents' physical fitness status and executive function. <bold>Methods:</bold> Using stratified whole group sampling, 5336 adolescents aged 13-18 were selected from six regions in China and were subjected to physical fitness tests, executive function tests and physical activity surveys. Pearson's correlation analysis was used to analyze the relationship between adolescents' physical fitness index, physical activity and executive function. Mediated effects models were fitted using the bootstrap mediation procedure in the PROCESS (version 4.2) SPSS macro prepared by Hayes, and the mediated effects of adolescent physical fitness index in the relationship between physical activity and executive function were examined using Model 4 in the PROCESS SPSS macro. <bold>Results:</bold> The correlation coefficients between adolescent physical fitness index and inhibitory control reaction time were all 0.00094, p &gt; 0.05; the correlation coefficients between adolescent physical fitness index and working memory (1-back and 2-back) reaction time were -0.13 and -0.093, respectively, p &lt; 0.05; the correlation coefficient between adolescent physical fitness index and cognitive flexibility reaction time was -0.17, p &lt; 0.05. The correlation coefficient between physical activity and physical fitness index in adolescents was 0.040, p &lt; 0.05. The mediated effect values of physical fitness index between physical activity and the refreshing function (1-back and 2-back) and the switching function were -0.005 (95%CI= -0.0143 – -0.0022), -0.0094 (95%CI= -0.0256 – -0.0044) and -0.0023 (95%CI= -0.0063 – -0.0010). <bold>Conclusion:</bold> There was a fully mediated effect of physical fitness index between physical activity and executive function.