London: Do you want your child to excel in the classroom? Then, better allow the kid to be physically active, a study by an Indian-origin researcher-led Dutch team has claimed.

How well children perform in the classroom could be linked to how physically active they are, according to a study by Dr Amika Singh and colleagues from the Vrije Universiteit University Medical Center in Amsterdam.

Writing in Archives of Pediatrics & Adolescent Medicine, the researchers said they found strong evidence of a link between exercise and academic performance.

The review looked at 14 studies involving more than 12,000 children.

Exercise may help by increasing blood and oxygen flow to the brain, the study said.

But the authors of the study said more accurate and reliable measurement instruments were needed to examine the link in greater detail.

Singh and colleagues were prompted to look at the relationship between physical activity and academic performance because of concerns that pressure to improve children's school marks could mean they spend more time in the classroom and less time doing physical activity.

So they identified 10 observational and four interventional studies for review.

Twelve of the studies were conducted in the United States, one in Canada and one in South Africa. Sample sizes ranged from 53 to about 12,000 participants between the ages of six and 18 years. The period of follow-up varied between eight weeks and more than five years.

Two of the studies reviewed were rated as being of high quality, the study says.

Researchers said they found strong evidence of a "significant positive relationship" between physical activity and academic performance using those two studies as evidence.

The study said this could be because exercise helps cognition by increasing blood and oxygen flow to the brain.

Physical activity could also reduce stress and improve mood, making children more likely to behave in the classroom.

"Children who learn to participate in sport also learn to obey rules. This may mean they are more disciplined and able to concentrate better during lessons," Singh said.

"People always ask, 'How much exercise do I need to do to get an A?' We don't know that but we would like to find out," said Singh.

"Children should be active for at least one hour a day, for health reasons. But we also need to look at other things, like what kind of activities they should do, when they should do them and for how long."

(Agencies)