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Purpose To evaluate changes in clustered cardiovascular disease (CVD) risk factors in 9-year-old children following a 2-year school-based physical activity intervention. Methods In total, 259 children (age 9.3 ± 0.3 years) were invited, of whom 256 participated. The intervention group (63 boys, 62 girls) carried out 60-minute teacher-controlled daily physical activity over two school years. The control group (62 boys, 69 girls) had the curriculum-defined amount of physical education (45 minutes twice each week). Of these, 67% (171 total, 91 intervention) successfully completed both baseline and post-intervention of six CVD risk factors: systolic blood pressure (SBP), triglyceride (TG), total cholesterol-to-high-density lipoprotein cholesterol ratio (TC:HDL ratio), waist circumference (WC), the homeostasis model assessment for insulin resistance (HOMA), and peak oxygen uptake (VO2peak). All variables were standardized by sex prior to constructing a cluster score (sum of z-scores for all variables). The effect of the intervention on the cluster score was analyzed using linear multiple regression. Results The cluster score improved after the intervention (ES = .29). Furthermore, the analyses showed significant effects in favor of the intervention group for systolic blood pressure (ES = .35), total cholesterol to HDL-c ratio (ES = .23), triglyceride (ES = .40), and VO2peak (ES = .57). Conclusion A teacher-led school-based physical activity intervention that is sufficiently long and includes a substantial amount of daily physical activity can beneficially modify children's clustered CVD risk profile. This article is protected by copyright. All rights reserved.

Agreement between and classification accuracy of six different noninvasive composite scores and a cardiovascular disease (CVD) risk factor score were investigated in 911 (466 boys and 445 girls) 10-year-old Norwegian children. A CVD risk factor score (triglyceride, total cholesterol/HDL ratio, homeostasis model assessment of insulin resistance, systolic blood pressure (SBP), waist-to-height ratio (WHtR), and cardiorespiratory fitness) and six noninvasive risk scores (fitness+three different measurements of fatness (body mass index (BMI), WHtR, and skinfolds), with and without inclusion of SBP) were calculated (mean z-score by gender). Agreement was assessed using Bland-Altman plots. The ability of noninvasive scores to correctly classify children with clustered CVD risk was examined by receiver operating characteristic (ROC) analysis and Cohen's kappa coefficient (κ). For both sexes, the noninvasive scores without SBP showed excellent AUC values (AUC=0.93-0.94, 95% CI=0.88-0.98) and moderate kappa values (κ=0.49-0.64) and had limits of agreement of 0.0±0.78-0.89 (arbitrary unit). Inclusion of SBP increased AUC values (AUC=0.96-0.97, 95% CI=0.94-0.99), kappa values (κ=0.58-0.69), and reduced limits of agreement (0.0±0.68-0.76). Noninvasive scores that include fitness and fatness provide acceptable agreement and classification accuracy, allowing for widespread early identification of children that might be at risk for developing CVD later in life. SBP should be included in the noninvasive score to improve classification accuracy if possible.

The aim of this study was to describe changes in children's cardiorespiratory fitness (CRF) following a school-based physical activity (PA) intervention. In total, 259 children (age 9.3 ± 0.3 years) were invited to participate, of whom 256 participated. The children from the intervention school (63 boys, 62 girls) carried out 60-min PA over 2 school years. The children from the control school (62 boys, 69 girls) had the regular curriculum-defined amount of physical education in school, i.e. 45 min twice weekly. One hundred and eighty-eight children (73.4%) successfully completed both the baseline and the post-intervention peak oxygen uptake (VO₂ peak) test. VO₂ peak was measured directly during a continuous progressive treadmill protocol where the children ran until exhaustion. The children from the intervention school increased their mean VO₂ peak (95% confidence interval) 3.6 (2.5-4.6) mL/kg/min more than the children from the control school. This VO₂ peak value was adjusted for both sex and baseline VO₂ peak. Boys and girls demonstrated similar VO₂ peak responses. The intervention, primarily carried out at a moderate intensity, had the biggest impact in children with low initial CRF levels. In conclusion, a 2-year school-based 60-min daily PA intervention significantly improved CRF in children.

Center for Research in Childhood Health, Institute of Sports Science andClinical Biomechanics, University of Southern Denmark, Odense, DenmarkCorresponding author: Geir K. Resaland, Faculty of Teacher Education and Sport, Sogn og Fjordane UniversityCollege, PO Box 133, N-6851 Sogndal, Norway. Tel: 147 41621333; 147 57676097, Fax: 147 57676333, E-mail: geirkr@hisf.noAccepted for publication 28 June 2010Theaimofthisstudywastoinvestigatetheeffectofa2-yearschool-based physical activity (PA) intervention in 9-year-old children on cardiovascular disease (CVD) risk factors.Oneinterventionschool(I-school)(n5125)andonecontrolschool (C-school) (n5131) were included. The children atthe I-school carried out 60min of PA daily. The PA lessonswere planned, organized and led by expert physical educa-tion (PE) teachers. In the C-school, children were offeredthe normal 45min of PE twice weekly. The interventionresulted in a greater beneficial development in systolic(P50.003) and diastolic (P50.002) blood pressure, totalcholesterol-to-high-density lipoprotein cholesterol ratio(P50.011), triglyceride (P50.030) and peak oxygenuptake (Po0.001) in I-school children than in C-schoolchildren. No significant differences were observed in waistcircumference, body mass index and the homeostasis modelassessment for insulin resistance between the two groups.Furthermore, the intervention, primarily carried out atmoderate intensity, had the strongest impact in childrenwiththeleastfavorablestartingpoint.Inconclusion,adailyschool-based PA intervention can beneficially modify chil-dren’s CVD risk profile if the intervention has sufficientdurationandincludesasubstantialamountofdailyPA,andif the PA is implemented by expert PE teachers.