Physical activity among Canadian children on school days and nonschool days.

BACKGROUND Schools are frequently cited as a favorable venue to promote physical activity (PA), however little data exist describing times when students are least active. Our objective was to overcome this limitation and describe time periods when students are least active. METHODS We used a cross-sectional design to assess patterns of PA in 923 grade 5 students [mean age: 10.9 (± 0.4) years] from 30 schools in Alberta, Canada. Students wore time-stamped pedometers for 9 consecutive days, providing 7 full days of data. We compared step counts adjusted for nonwear time between school days and nonschool days as well as during school hours and after school hours. RESULTS 689 (75%) students provided complete data. The average daily step count was higher on school days (boys 13,476 ± 4123 step/day; girls 11,436 ± 3158 steps/day) than nonschool days (boys 11,009 ± 5542 steps/day; girls 10,256 ± 5206 steps/day). More steps were also taken during school hours than nonschool hours (boys +206 ± 420 steps/hour, P < .001; girls 210 ± 347, P < .001 steps/hour). CONCLUSIONS PA levels of children are below Canadian recommended levels for optimal growth and health. Health promotion should emphasize PA particularly among girls, outside school hours, and weekends.