This experiment tested the hypothesis that exercise would improve executive function. Sedentary, overweight 7- to 11-year-old children (N = 171, 56% girls, 61% Black, M ± SD age = 9.3 ± 1.0 years, body mass index [BMI] = 26 ± 4.6 kg/m², BMI z-score = 2.1 ± 0.4) were randomized to 13 ± 1.6 weeks of an exercise program (20 or 40 min/day), or a control condition. Blinded, standardized psychological evaluations (Cognitive Assessment System and Woodcock-Johnson Tests of Achievement III) assessed cognition and academic achievement. Functional MRI measured brain activity during executive function tasks. Intent to treat analysis revealed dose-response benefits of exercise on executive function and mathematics achievement. Preliminary evidence of increased bilateral prefrontal cortex activity and reduced bilateral posterior parietal cortex activity attributable to exercise was also observed. Consistent with results obtained in older adults, a specific improvement on executive function and brain activation changes attributable to exercise were observed. The cognitive and achievement results add evidence of dose-response and extend experimental evidence into childhood. This study provides information on an educational outcome. Besides its importance for maintaining weight and reducing health risks during a childhood obesity epidemic, physical activity may prove to be a simple, important method of enhancing aspects of children's mental functioning that are central to cognitive development. This information may persuade educators to implement vigorous physical activity. (PsycINFO Database Record (c) 2010 APA, all rights reserved).
