How school time physical activity is the "big one" for daily activity among schoolchildren: a semi-experimental approach.
BACKGROUND
This study was designed to model the relationship between an ActiGraph-based "in-school" physical activity (PA) and the daily one among children and to quantify how school can contribute to the daily PA recommendations.


METHODS
Fifty boys and 43 girls (aged 8 to 11 years) wore ActiGraph for 2 schooldays of no structured PA. The daily moderate-to-vigorous PA (MVPA(d)) was regressed on the school time MVPA (MVPA(s)). Then, a ROC analysis was computed to define the required MVPA(s).


RESULTS
Children spent 57% of their awaking time at school. School time PA opportunities (ie, recesses: approximately 18% of a child's awaking time) accounted for > 70% of the MVPA(d) among children. Then, MVPA(d) (Y) could be predicted from MVPA(s) (X) using the equation: Y= 2.06 X0.88; R2 = .889, P < .0001. Although, this model was sex-specifically determined, cross-validations showed valid estimates of MVPA(d). Finally, with a sensitivity of 100% and a specificity of 90%, MVPA(s), a 34 min x d(-1) was required to prompt the daily recommendation.


CONCLUSIONS
The current study shows the contribution of MVPA at school to recommended activity levels and suggests the value of activity performed during recesses. It also calls for encouraging both home- and community-based interventions, predominantly directed toward girls.
Institute of Engineering in Health of Lille, Laboratory of Public Health, EA 2694 (University of Lille 2), Loos, France.
Benjamin C
BC
Guinhouya
Mohamed
M
Lemdani
Christian
C
Vilhelm
Hervé
H
Hubert
Géoffroy K
GK
Apété
Alain
A
Durocher
D001837:Body Weights and Measures; D002648:Child; D003430:Cross-Sectional Studies; D015444:Exercise; D005260:Female; D006801:Humans; D008297:Male; D018670:Monitoring, Ambulatory; D050177:Overweight / Q000517:prevention & control; D012574:Schools / Q000458:organization & administration*; D012737:Sex Factors; D013997:Time Factors