Relationships of academic achievement (government tests) with physical fitness (multistage run), physical activity (pedometers) and percent body fat (dual emission X-ray absorptiometry) were examined at both the aggregate school level and the individual child level using data collected from 757 children in 29 elementary schools. Statistical adjustments included gender, grade and socioeconomic status.
TELFORD, D., Cunningham, R., Telford, R., & Abharatna, W. (2012). Schools with fitter children achieve better literacy and numeracy results: Evidence of a school cultural effect. Pediatric Exercise Science, 24(1), 45-57. https://doi.org/10.1123/pes.24.1.45