The Ulster Teachers Union (UTU) says it welcomes research which shows children’s fitness levels may have an impact on how well they do in exams.
Researchers from the University of Granada in Spain found aerobic capacity and motor ability was associated with a greater volume of gray matter.
Those who exercised for at least three nights a week had more grey matter in areas of the brain linked to reading and verbal communication.
The fitter the youngster became the greater the change, they found.
UTU general secretary Avril Hall Callaghan says the findings are exciting.
They come as hundreds of girls from the North also took part in a separate study looking at why their gender does not exercise as much as boys.
The Women in Sport study says PE is “perceived as an unimportant subject for girls to be good at, despite its impact in developing valuable life-skills such as team-work and self-confidence”.
Ms Hall Callaghan said: “Despite a summer full of women’s sport in Northern Ireland – the UEFA Women’s Under-19s Championship and the Women’s Rugby World Cup – and although things are starting to change slowly, there are still many barriers to girls taking part in sport.
“Now girls from Northern Ireland have helped provide information so changes can be made which will hopefully enable more of them to take part in sport and benefit as a result – maybe even improve their academic achievement.”
Finding out which sports and activities the girls enjoy in primary school and immediately engaging them in those when they get to secondary school, will go some way to help, she suggests.
“We would urge decision-makers and funders to take all this on board and make this new year one that really counts for our young people, their good health and their academic achievement.”