There was some evidence that school-based physical activity interventions had a positive impact on four of the nine outcome measures .
Specifically positive effects were observed for duration of physical activity , television viewing , VO2 max , and blood cholesterol .
Generally , school-based interventions had little effect on physical activity rates , systolic and diastolic blood pressure , BMI , and pulse rate .
At a minimum , a combination of printed educational material s and changes to the school curriculum that promote physical activity result ed in positive effects .
Few changes in outcomes were observed in this up date with the exception of blood cholesterol and physical activity rates .
For example blood cholesterol was no longer positively impacted upon by school-based physical activity interventions .
The evidence suggests the ongoing implementation of school-based physical activity interventions at this time , given the positive effects on behavior and one physical health status measure .
BACKGROUND The World Health Organization ( WHO ) estimates that 1.9 million deaths worldwide are attributable to physical inactivity and at least 2.6 million deaths are a result of being overweight or obese .
In addition , WHO estimates that physical inactivity causes 10 % to 16 % of cases each of breast cancer , colon , and rectal cancers as well as type 2 diabetes , and 22 % of coronary heart disease and the burden of these and other chronic diseases has rapidly increased in recent decades .
OBJECTIVES The purpose of this systematic review was to summarize the evidence of the effectiveness of school-based interventions in promoting physical activity and fitness in children and adolescents .
Reducing children's television viewing to prevent obesity: a randomized controlled trial.
CONTEXT Some observational studies have found an association between television viewing and child and adolescent adiposity .  OBJECTIVE To assess the effects of reducing television , videotape , and video game use on changes in adiposity , physical activity , and dietary intake . DESIGN R and omized controlled school-based trial conducted from September 1996 to April 1997 . SETTING Two sociodemographically and scholastically matched public elementary schools in San Jose , Calif. PARTICIPANTS Of 198 third- and fourth- grade students , who were given parental consent to participate , 192 students ( mean age , 8.9 years ) completed the study . INTERVENTION Children in 1 elementary school received an 18-lesson , 6-month classroom curriculum to reduce television , videotape , and video game use . MAIN OUTCOME MEASURES Changes in measures of height , weight , triceps skinfold thickness , waist and hip circumferences , and cardiorespiratory fitness ; self-reported media use , physical activity , and dietary behaviors ; and parental report of child and family behaviors . The primary outcome measure was body mass index , calculated as weight in kilograms divided by the square of height in meters . RESULTS Compared with controls , children in the intervention group had statistically significant relative decreases in body mass index ( intervention vs control change : 18.38 to 18.67 kg/m2 vs 18.10 to 18.81 kg/m2 , respectively ; adjusted difference -0.45 kg/m2 [ 95 % confidence interval [ CI ] , -0.73 to -0.17 ] ; P = .002 ) , triceps skinfold thickness ( intervention vs control change : 14.55 to 15.47 mm vs 13.97 to 16.46 mm , respectively ; adjusted difference , -1.47 mm [ 95 % CI , -2.41 to -0.54 ] ; P=.002 ) , waist circumference ( intervention vs control change : 60.48 to 63.57 cm vs 59.51 to 64.73 cm , respectively ; adjusted difference , -2.30 cm [ 95 % CI , -3.27 to -1.33 ] ; P<.001 ) , and waist-to-hip ratio ( intervention vs control change : 0.83 to 0.83 vs 0.82 to 0.84 , respectively ; adjusted difference , -0.02 [ 95 % CI , -0.03 to -0.01 ] ; P<.001 ) . Relative to controls , intervention group changes were accompanied by statistically significant decreases in children 's reported television viewing and meals eaten in front of the television . There were no statistically significant differences between groups for changes in high-fat food intake , moderate-to-vigorous physical activity , and cardiorespiratory fitness . CONCLUSIONS Reducing television , videotape , and video game use may be a promising , population -based approach to prevent childhood obesity
There was some evidence that school-based physical activity interventions had a positive impact on four of the nine outcome measures .
Specifically positive effects were observed for duration of physical activity , television viewing , VO2 max , and blood cholesterol .
Generally , school-based interventions had little effect on physical activity rates , systolic and diastolic blood pressure , BMI , and pulse rate .
At a minimum , a combination of printed educational material s and changes to the school curriculum that promote physical activity result ed in positive effects .
Few changes in outcomes were observed in this up date with the exception of blood cholesterol and physical activity rates .
For example blood cholesterol was no longer positively impacted upon by school-based physical activity interventions .
The evidence suggests the ongoing implementation of school-based physical activity interventions at this time , given the positive effects on behavior and one physical health status measure .
BACKGROUND The World Health Organization ( WHO ) estimates that 1.9 million deaths worldwide are attributable to physical inactivity and at least 2.6 million deaths are a result of being overweight or obese .
In addition , WHO estimates that physical inactivity causes 10 % to 16 % of cases each of breast cancer , colon , and rectal cancers as well as type 2 diabetes , and 22 % of coronary heart disease and the burden of these and other chronic diseases has rapidly increased in recent decades .
OBJECTIVES The purpose of this systematic review was to summarize the evidence of the effectiveness of school-based interventions in promoting physical activity and fitness in children and adolescents .