Parents, if you want to smarter children let them play outside. A new study published in the Archives of Pediatrics & Adolescent Medicine found a direct link between physical activity and the academic performance of school children.

Researchers at the Vrije Universiteit University Medical Center in the Netherlands set out to study new policies that put emphasis on more class time to improve test scores as opposed to physical activity.  Researchers, led by Amika Singh, Ph.D., looked at 12 studies involving 12,000 children ages 6 to 18 in the United States, Canada and South Africa.

“According to the best evidence synthesis, we found strong evidence of a significant positive relationship between physical activity and academic performance. The finding of one high quality intervention study and one high quality observation study suggest that being more physically active is positively related to improved academic performance in children,” Singh said in a statement.

The study also showed that exercise increased oxygen and blood flow to the brain, which in turn stimulates brain activity. Past studies have had similar findings.

In an August 2011 issue of Brain, Behavior and Immunity, it was revealed that physical activity is particularly beneficial to the elderly, and can diminish brain damage associated with Alzheimer Disease. “Exercise allows the brain to rapidly produce chemicals that prevent damaging inflammation,” said Professor Jean Harry who conducted the 2011 study.

Researchers in Amsterdam believe that the relationship between physical activity and academic performance should be further explored, and added that among all of the studies concerning academic improvement, none of them used physical activity as a component of scholastic achievement.

“More high-quality studies are needed on the dose-response relationship between physical activity and academic performance and on the explanatory mechanisms, using reliable and valid measurement instruments to assess this relationship accurately,” Singh said.