Exercise Means Success for Overweight Children

Summary
Physical activity is known to benefit brain function and could influence neural and cognitive development in childhood. This study of overweight sedentary children found that physical exercise improved the executive function of their brains and academic performance even in the abstract domain of mathematics without special instructions. Functional MRIs done on a few of the participants showed altered cortical activity in two significant, different areas of the brain. The findings from this study might impact the formulation of future education policy.

Introduction
Executive function of the brain includes supervisory control of goal-directed behavior. To execute a task, allocation of memory and attention, goal setting, self-control, self-monitoring, and competent flexible application of strategies is needed. The prefrontal region of the brain is involved in executive function. In adults, it was found that aerobic exercise improves executive function with a corresponding increase in the cortical activity in the prefrontal area. Past studies also showed that vigorous exercise improves academic grades in children. This study attempted to find out whether overweight children would benefit in academic achievement by participating in aerobic exercises. It also tested if the amount of exercise was linked to the level of improvement in academic grades.

Methodology
* The study involved 171 overweight children between 7 and 11 years of age with sedentary lifestyles. They were divided into three groups. The control group participated in no exercises, the low dose group exercised for 20 minutes/day, and the high dose group exercised for 40 minutes/day.
* Exercises were designed for pleasure intensity and safety and not for skill development or competition. Activities included jumping rope, running games, modified basketball and soccer. Children were encouraged to raise their heart rate above 150 beats/minute during exercise. This was to ensure an optimum aerobic exercise load. The exercise program lasted 13 weeks.
* A standardized psychological battery gauged achievement and cognition at baseline and after completion of experiments.
* Twenty children from the study also participated in a functional MRI study consisting of baseline and post-study images.

Results
* Planning, paying attention and carrying out action sequences are involved in executive brain function. On an average, the baseline planning score was 101.3 for boys and 105.2 for girls. The average attention score was 99.8 for boys and 107.5 for girls.
* The low-dose and high-dose exercise groups showed improved scores on planning scales after completion of experiments compared to baseline. There was no such significant gain in the control group.
* The “broad math achievement’ is a subtest used for documenting children’s academic achievement. The high-dose exercise group had an average score of 107 on this scale, as compared to 104 in the control group.
* Functional MRI showed increased activity in the prefrontal cortex and diminished activity in the posterior parietal cortical areas on both sides after exercise.

Next steps/Shortcomings
The findings are based on research involving overweight 7- to 11-year-old children. The results might differ for lean children and other age groups. Whether improvement noted in cognitive functions persists, even after exercises are stopped, is not known. Social interactions improve during the exercise sessions. This might change psychological functions, and benefits noted might not be due to exercise alone. The fMRI experiments showed increased cortical activation in prefrontal and reduced activity in posterior parietal areas on both sides in the exercise group. This indicates against possible global improvement in brain activity. Also, the MRI experiments were performed in a very small group and did not test dose-response. More research must address these issues.

Conclusion
Physical exercise helps maintain weight and lower health risks in every age group. The findings of this study suggest that overweight children improve executive function and academic performance after participating in aerobic exercises. Beneficial effects of exercises on mathematical achievement are noteworthy because additional math teaching was not provided. This indicates that changed brain function after physical exercise might help in problem solving and abstract thinking capacities. This effect may have important implications for child development and educational policy regarding the necessity for brisk physical activity. As incidence of obesity is increasing in children, exercise would help them to improve both physical and mental health.

For More Information:
Exercise Improves Executive Function, Achievement and Alters Brain Activation in Overweight Children
Publication Journal: Health Psychology, 2011
By Catherine L. Davis; Phillip D. Tomporowski; Medical College of Georgia, Augusta, Georgia, and the University of Georgia
*FYI Living Lab Reports Are Summaries of the Original Research.