School-based physical activity: Has benefits even if it doesn't help lose weight

School-based health and exercise programs have positive outcomes despite having little effect on children's weight or the amount of exercise they do outside of school, say Cochrane Researchers who carried out a systematic review of studies on physical activity programs in schools. The research shows that school-based programs increased the time children spent exercising and reduced the time spent watching television. Programs also reduced blood cholesterol levels and improved fitness – as measured by lung capacity. However, programs made little impact on weight, blood pressure or leisure time activities.

Physical inactivity is a key factor behind 1.9 million deaths every year and almost a quarter of all cases of coronary heart disease. People who are overweight as children are more likely to develop heart disease as adults. Exercise helps to maintain a healthy weight, yet studies show most children do not do enough exercise to give any health benefit. The World Health Organisation has identified schools as important settings for promotion of physical activity among children.

The researchers reviewed data from 26 studies of physical activity promotion programs in schools in Australia, South America, Europe and North America. Most studies tried to encourage children to exercise by explaining the health benefits and changing the school curriculum to include more physical activity for children during school hours. Programs included teacher training, educational materials and providing access to fitness equipment.

"Given that there are at least some beneficial effects, we would recommend that schools continue their health promotion programs. These activities should also be supported by public health unit staff, and parents and teachers as positive role models," says lead researcher, Maureen Dobbins, who works at the School of Nursing at McMaster University in Ontario, Canada.

Dobbins believes that schools should make spaces in their timetables to create environments that encourage pupils to engage in physical activity each day as well as having an ethos that encourages increased duration of moderate to vigorous activity each week. "Schools have great opportunities to help pupils learn how to promote health and minimise the risk of acquiring a chronic disease. Providing a healthy structure to their day should enable them to develop healthier lifestyles that may track in adulthood," she says.

She also suggests an explanation for why some programs often don't improve physical health measures such as weight and blood pressure. "Physical activity classes may be too closely associated with school work, so for some students this makes them feel like they are being made to do more work. Perhaps the key is to promote physical activity by getting children and adolescents to 'play' in ways that promote better fitness levels, while at the same time represent fun and adventurous activities," says Dobbins.

Source: Wiley-Blackwell