Oct. 29 (HealthDay News) -- Three months of daily, vigorous exercise can improve overweight kids' thinking, U.S. researchers report.

Physical activity can also lower their diabetes risk, reduce their body fat, and strengthen their bones, says a team that looked at about 200 overweight, inactive children, ages 7 to 11.

All the children learned about healthy nutrition and the benefits of physical activity. In addition, a third of the children exercised 20 minutes a day, and another third exercised for 40 minutes. During the exercise sessions, the children played running games and used hula hoops and jump ropes to get their heart rates to 79 percent of maximum -- considered a vigorous workout.

"Aerobic exercise training showed dose-response benefits on executive function (decision-making) and possibly math achievement, in overweight children," the researchers wrote in an abstract presented this week at The Obesity Society's annual scientific meeting in New Orleans. "Regular exercise may be a simple, important method of enhancing children's cognitive and academic development. These results may persuade educators to implement vigorous physical activity curricula during a childhood obesity epidemic," the researchers concluded.

"Is exercise a magic wand that turns them into lean, healthy kids? No. They are still overweight but less so, with less fat, a healthier metabolism and an improved ability to handle life," lead investigator Dr. Catherine Davis, a clinical health psychologist at the Medical College of Georgia, in Augusta, said in a prepared statement.

"We hope these findings will help persuade policymakers, schools and communities that time spent being physically active enhances, rather than detracts from learning," Davis said.

SOURCE: Medical College of Georgia, news release, Oct. 22, 2007