Eric Wan, front, exercises with other Grade 2 students during their daily 30-minute gym class at Scarborough's Chartland Junior Public School March 30, 2009.
Gym class a day won't keep obesity at bay
March 31, 2009
STAFF REPORTER
Note: This article has been edited to correct a previously published version.
Compulsory gym class in school does little to reduce childhood obesity, meaning more must be done after school to curb the growing fat epidemic, according to a study.
The findings, released yesterday in the Canadian Medical Association Journal, contradict the push for more physical activity in school to fight childhood obesity, said Dr. Kevin Harris, a pediatrician at BC Children's Hospital and the study's lead author.
"While some may like to promote (physical activity in school) as a means of improving childhood obesity, it's clear that these interventions won't solve the problem," he said.
In Canada, childhood overweight and obesity rates have quadrupled in the past 40 years and now stand at about 30 per cent. The solution to the epidemic, many have long argued, must start at home.
Harris stressed the study does not try to diminish efforts to increase physical activity in school, which he said is important for improving cardiovascular health, reducing blood pressure, and increasing lean muscle mass, aerobic capacity and flexibility in children. But it alone doesn't reduce overall weight or fat, since diet might have a bigger influence on body composition and weight than physical activity. The findings are a good reminder that more than exercise at school is needed to help children lose weight.
"I think in some places, physical activity is promoted as a central component to combat childhood obesity, and based on the results of our study, I don't think it should continue to be promoted that way," said Harris.
In Ontario, gym classes are mandatory from kindergarten to Grade 8 and a daily 20-minute dose of exercise also became compulsory in 2005. Suitable exercises include a variety of games and activities, such as playing tag or skipping rope.
At the time, the government invested $10.7 million in one-time funding for training and implementation of the program – over and beyond annual costs for physical education program.
Some school boards, such as the Toronto public board, allocate 150 minutes weekly for physical education, said Kelly Baker, a spokesperson for the board.
Harris and his colleagues reviewed 18 studies involving 18,141 elementary students in Canada, the U.S. and Europe who participated in school physical activity programs. They found the body mass index, a primary obesity indicator, did not decrease among students involved in school-based physical activity, when compared with students in a control group.
There were also no significant changes or decreases in other measures for obesity, including body fat, waist circumference and waist-to-hip ratio.
Dealing with the problem has to start at home, says Jennifer Cowie Bonne, the director of marketing and development for the Ontario Physical and Health Education Association. "It's a shared responsibility and in some cases, if a school is doing something for physical activity, how is that being reinforced at home and in the broader community," said Bonne.
A commentary on the study in the same Journal issue, written by Dr. Louise Baur from the University of Sydney, suggests a more comprehensive approach to obesity, including providing healthy school meals, improved urban planning and subsidies on vegetables and fruit for schools.
Many of these efforts are already in place, but have yet to make a difference, says Dr. Danielle Grenier, Medical Affairs Director at the Canadian Pediatric Society.
"A lot of schools are moving towards healthy foods and promoting health, but I don't think we will see anything change for another decade," she said. "It is going to take time to change habits."
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