A new international collaboration led by Japanese researchers suggests regular physical activity improves cognitive ability in kids, especially those who initially showed deficits in executive skills.

The findings run counter to the common school-age stereotype that smart kids are unathletic.

Researchers note that historically, findings regarding the effects of regular physical activity on cognition in children have been inconsistent due to a number of demographic factors and experimental considerations. However, there is growing evidence that regular physical activity (PA) is an efficacious and low-cost health behavior that supports cognitive and brain development in children and adolescents.

Associate Professor Keita Kamijo at the University of Tsukuba and Assistant Professor Toru Ishihara at Kobe University led the research. They and their colleagues re-analyzed data from previous experiments in which executive function was assessed in children before and after several months of daily intervention with physical activity. The activities included aerobic activities, ball games and playing tag.

Executive functions refer to three types of cognitive skills. The first is the ability to suppress impulses and inhibit reflex-like behaviors or habits. To assess this ability, children were asked to indicate the color in which words like “red” and “blue” were displayed on a computer screen. This is easy when the words and colors match (“red” displayed in red font), but often requires inhibition of a reflex response when they don’t (“red” displayed in blue font).

The second skill is the ability to hold information in working memory and process it. This was evaluated by testing how well children could remember strings of letters that vary in length.

The third cognitive skill is mental flexibility. This was measured by asking children to frequently switch the rules for categorizing colored circles and squares from shape-based to color-based.

Investigators found that physical activity is linked to better cognitive ability, which is in turn related to academic performance in school. Researchers admit that understanding the effects of physical activity on cognition has been difficult for several reasons. “Previous studies looked at the issue too broadly,” explains Professor Kamijo, “When we broke down the data, we were able to see that physical activity helps children the most if they start out with poor executive function.”

Researchers then discovered a factor that was missed in the initial analyses. They found that cognitive skills, which have been shown to closely associate with academic performance, improved most in children whose skills were initially poor.

The team also found that increased time spent doing regular physical activity did not negatively affect cognitive function in children who started out with better cognitive functions.

The finding that daily physical activity can improve executive function in children who might need it the most has some practical implications.

“Because the cognitive functions evaluated in our study are related to academic performance,” said Kamijo, “we can say that daily physical activity is critical for school-aged children. Our findings can help educational institutions design appropriate systems for maximizing the effects of physical activity and exercise.”

The study appears online in the Journal of Clinical Medicine.

Source: University of Tsukuba/EurekAlert