Just an extra two hours of exercise each week can reportedly improve school performance, according to a new study.

Scientists with the University of Gothenburg tested the theory among a group of 12 years olds who were given two hours of extra play and motion activities per week, in collaboration with a local sports club - two more hours than usual.

Previous studies have found a link between exercise and cognition, in addition to cardiovascular fitness, IQ and brain resilience in young adults, and now this new study demonstrates its association with school performance as well.

To determine whether students' performance indeed improved from the extra endorphins, researchers compared the achievement of national learning goals by the children four years before and five years after they implemented the increased activity. There was also a control group of kids who did not partake in added physical activity.

The results seem to speak for themselves: A larger proportion of students in the intervention school didn't just benefit from more exercise, but their school performance improved as well. They achieved 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, a deterioration," scientist and neurologist Thomas Lindén at the Sahlgrenska Academy said in a statement.

Scientists do point out that they could not control for all factors, such as gender, parent education, and ethnic background, but still they are confident that extra physical activity "helps children succeed in school."

"In an in-depth study we further investigate gender differences, psychological health and mechanisms behind the observed effects," researcher Dr. Bunketorp Käll further explained.

"It's being discussed whether more physical education in school would take time from academic subjects, and in this way weaken school performance," added Lindén. "Our study shows that exactly the opposite may be the case."

The results were published in the Journal of School Health.