by Kim Painter, Special for USA TODAY
Programs aimed at increasing the physical activity of children have so far failed to get kids moving very much, says a new research review.
That failure to boost how much kids walk, run, jump and otherwise move around during the day helps explain why the programs also have failed to put a dent in child obesity, say researchers who pooled results from 30 studies for the new study published Thursday in the BMJ.
The idea that after-school exercise clubs, extra physical education classes and other programs will boost activity and reduce obesity makes sense to many people, but "unfortunately, it's not working," says lead researcher Brad Metcalf, a statistician and research fellow at Peninsula College of Medicine and Dentistry, Plymouth University, United Kingdom.
Metcalf and colleagues looked only at studies in which children wore motion sensors -- called accelerometers -- to measure all-day activity levels. Previous reviews relied on questionnaires, which are less reliable, Metcalf says. The studies included more than 14,000 children, many in the USA.
Taken together, the results suggest that formal physical activity programs result in a "small to negligible increase" in movement through the day, the researchers write. When they looked only at moderate to intense physical activity, such as brisk walking or running, they found a somewhat more noticeable increase -- 4 minutes a day.
The researchers speculate that kids either didn't move much during their clubs and classes or that they compensated by moving less at other times. It's also possible, they say, that the programs just replaced equally active playtime for some kids. The study did not look at obesity, but other studies have suggested such programs have little effect on weight, the researchers say.
The results are "disappointing" but no reason to give up on efforts to get kids moving, says Mark Hamer, a researcher at University College London who wrote an editorial accompanying the study. Physical activity, combined with diet, can help control weight, he says, but it also boosts cardiovascular and mental health and has many other benefits. And active kids, he says, are more likely to become active adults.
"We know physical activity is important," he says. "What we're not good at is designing behavioral interventions that increase it."
Some individual studies have shown better results, but it's true that overall results have been "modest" and "we haven't hit any home runs yet," says Russell Pate, an exercise physiologist who leads research on children and physical activity at the University of South Carolina, Columbia.
Pate helped put together federal guidelines that call for U.S. children to get at least 60 minutes of physical activity a day. He says it may be crucial to give kids many chances to move each day -- during classroom breaks, at recess, after school, at home and in physical education classes. Getting more kids walking or biking to school also could help, he says.
A panel of U.S. experts is looking at physical activity programs to see what is and is not working and should report next year, Pate says.
He adds: "I have a lot of optimism that we really can make a difference."