Associations of physical fitness and academic performance among schoolchildren.

BACKGROUND: Public schools provide opportunities for physical activity and fitness surveillance, but are evaluated and funded based on students' academic performance, not their physical fitness. Empirical research evaluating the connections between fitness and academic performance is needed to justify curriculum allocations to physical activity programs.
METHODS: Analyses were based on a convenience sample of 254,743 individually matched standardized academic (TAKS™) and fitness (FITNESSGRAM(®) ) test records of students, grades 3-11, collected by 13 Texas school districts. We categorized fitness results in quintiles by age and gender and used mixed effects regression models to compare the academic performance of the top and bottom fitness groups for each test.
RESULTS: All fitness variables except body mass index (BMI) showed significant, positive associations with academic performance after adjustment for socio-demographic covariates, with standardized mean difference effect sizes ranging from .07 to .34. Cardiovascular fitness showed the largest interquintile difference in TAKS score (32-75 points), followed by curl-ups. Additional adjustment for BMI and curl-ups showed dose-response associations between cardiovascular fitness and academic scores (p < .001 for both genders and outcomes). Analysis of BMI demonstrated limited, nonlinear association with academic performance after socio-demographic and fitness adjustments.
CONCLUSIONS: Fitness was strongly and significantly related to academic performance. Cardiovascular fitness showed a dose-response association with academic performance independent of other socio-demographic and fitness variables. The association appears to peak in late middle to early high school. We recommend that policymakers consider physical education (PE) mandates in middle high school, school administrators consider increasing PE time, and PE practitioners emphasize cardiovascular fitness.