Toronto, Sep 29 (IANS): Girls - but not boys - who participate actively in school sports in middle childhood show improved behaviour and attentiveness in early adolescence, say researchers.

"Girls who do regular extracurricular sports between ages 6 and 10 show fewer symptoms of attention deficit/hyperactivity disorder (ADHD) at age 12, compared to girls who do not," said study author Linda Pagani from the University of Montreal in Canada.

"Surprisingly, however, boys do not appear to gain any behavioural benefit from sustained involvement in sports during middle childhood," Pagani added.

According to the study, published in the journal Preventative Medicine, ADHD harms children's ability to process information and learn at school.

Sport helps young people develop life skills and supportive relationships with their peers and adults. It offers a chance to get organized under some form of adult influence or supervision.

The research team came to their conclusions after examining data from a Quebec cohort of children born in 1997 and 1998, part of the Quebec Longitudinal Study of Child Development coordinated by the Institut de la Statistique du Québec.

Parents of the 991 girls and 1,006 boys in the study reported on whether their sons and daughters were in an extracurricular physical activity that required a coach or instructor between ages 6 and 10.

At age 12 years, teachers rated the children's behaviour compared to their classmates.

The research team then analysed the data to identify any significant link between sustained participation and later ADHD symptoms, discarding many possible confounding factors.

"Our goal was to eliminate any pre-existing conditions of the children or families that could throw a different light on our results," said Pagani.

In childhood, boys with ADHD are more impulsive and more motor-skilled than girls -- as a result, boys are more likely to receive medication for their ADHD, according to the study.

In girls, on the other hand, ADHD is more likely to go undetected -- and girls' difficulties maybe even more tolerated at home and in school.

"Parents of boys, by contrast, might be more inclined to enrol them in sports and other physical activities to help them," Pagani said.

"Sports activities in early childhood can help girls develop essential social skills that will be useful later and ultimately play a key role in their personal, financial and economic success," the authors wrote.