Exercise improves school performance, according to a recent study.

Researchers from the University of Gothenburg found that just two hours of extra physical activity each week can stimulate learning and improve school performance.

For the study, researchers collected data from more than 400 12-year-olds. The study participants were given two hours of extra play and motion activities per week, in collaboration with a local sports club. This was approximately twice the normal amount of curricular physical activity.

The effect of the intervention was evaluated by comparing the achievement of national learning goals by the children four years before and five years after its implementation. The results were compared to control groups in three schools that did not receive extra physical activity.

Researchers found that a larger proportion on students in the intervention school did achieve the national learning goals in all subjects examined -- Swedish, English and mathematics compared to the control groups.

"You can express it that two hours of extra physical education each week doubled the odds that a pupil achieves the national learning goals. We did not see a corresponding improvement in the control schools, where the pupils did not receive extra physical activity -- rather the contrary, deterioration," said researcher Thomas Linden of Sahlgrenska Academy.

The results from this study are in line with other studies in both animals and humans demonstrating links between physical activity and cognition.

"We have obtained a significantly better understanding of the mechanisms of learning in recent years. And it's very gratifying to be able to conclude that it is possible to improve the school performance of young pupils with relatively simple means," Linden said.

The findings were published in the scientific periodical Journal of School Health.