TORONTO - A review of studies on beefed-up physical activity programs in schools found the interventions have some health benefits but little effect on the amount of exercise the kids do outside school.
Researchers went over data from 26 studies in North America, Europe, South America and Australia as part of a Cochrane review, published Wednesday in the Cochrane Library. No studies from Canada were included, but the lead researcher is based at McMaster University in Hamilton.
"Generally what we found was that school-based physical activity interventions are effective in getting kids to spend more time being physically active during school hours," said Maureen Dobbins, an associate professor at the university's School of Nursing.
"We did see a few studies demonstrate a positive impact on less television viewing ... What we also found was increased lung capacity."
However, there was little impact on weight or blood pressure, the review indicated.
But Dobbins suggested that measuring weight or focusing on body mass index, or BMI, isn't really an "appropriate outcome measure" because these were growing kids from the ages of six to 18.
"If we just think about weight, if you have the majority of your subjects - your students - that you're studying that are at an appropriate BMI ... then we wouldn't necessarily want to be resulting in a lower BMI or a lower weight with kids that are already at an OK weight."
The interventions in some programs involved teachers being trained to build more physical activity into non-phys-ed courses, she said.
Or there might be a "super phys-ed class" that would keep children "with an elevated heart rate for the whole gym class as opposed to different sports that might have kids sitting out, rotating on and off the court."
A control group was offered regular phys-ed classes, she said.
Many of the programs tried to keep the activities fun and engaging, and some removed the competitiveness.
In addition, the children were taught about the importance of physical activity to their health through materials geared for them, and for their families.
"What was disappointing was that we're not seeing more kids being engaged in physical activity outside of school," Dobbins said.
"How can we get a larger proportion of the population to be engaging in physical activity?"
"We need to have other strategies that really focus on getting children, and likely families, to be more active outside of those school hours."
She also highlighted evidence suggesting that the interventions have a different impact on boys and girls.
"So we need to understand that better ... one physical activity program may be more effective for boys than girls, and vice versa, so we likely need to tailor physical activity promotion according to gender."
