Physical Activity, Self-Administered Motor Tests, and Academic Achievement in Lower Secondary School Students: A Cross-Sectional Study

Background: Physical activity is widely recognized as an important determinant of health and cognitive development; however, the association between specific components of motor performance and academic achievement remains incompletely understood. This cross-sectional study investigated the relationships between self-reported physical activity, self-administered motor tests, and self-reported academic achievement in lower secondary school students. Methods: A cross-sectional observational study was conducted involving 113 lower secondary school students (mean age: 12 years; 66 males and 47 females). Self-reported weekly physical activity and self-reported Grade Point Average (GPA) were collected using an online questionnaire. Following standardized familiarization during physical education classes, students self-administered the Stork Balance Stand Test, Plate Tapping Test, and Illinois Agility Test, whereas choice reaction performance was assessed individually under standardized conditions using the FITLIGHT Trainer system. Pearson’s correlation analyses, one-way ANOVA, and multiple linear regression were performed. Results: Weekly physical activity showed a strong positive correlation with GPA (r = 0.654, FDR-adjusted p < 0.001) and significant FDR-adjusted associations with upper-limb speed and choice reaction performance, whereas its associations with balance and agility did not remain statistically significant after correction for multiple comparisons. In the multiple regression analysis, weekly physical activity was the only variable independently associated with GPA (β = 0.639, p < 0.001), whereas balance, upper-limb speed, choice reaction performance, and agility were not independently associated with academic achievement after adjustment for age, sex, and school grade. The regression model explained 57.3% of the variance in GPA (adjusted R2 = 0.535; p < 0.001). Conclusions: In this sample of lower secondary school students, self-reported weekly physical activity was independently associated with self-reported academic achievement, whereas the assessed motor performance measures were not independently associated with GPA after adjustment for demographic variables. Given the cross-sectional design and reliance on self-reported measures, these findings should be interpreted as associative rather than causal. Further longitudinal studies using objective measures of physical activity and validated school-based motor assessment protocols are warranted.