Abstract
OBJECTIVE: To evaluate the relationship between physical activity (PA, min/school-day) at school and body mass index (BMI, kg/m(2)) among rural elementary-aged children. METHODS: Height (cm), weight (kg), and PA were measured for 1767 children (5-12 years) enrolled in six rural Oregon elementary schools in fall, 2013. PA at school was measured over four days using Walk4Life pedometers. Children with ≥ 3 valid monitoring days (n = 1482) were included in analyses. Means (min/d) were calculated for wear time, total PA (TPA: combined light, moderate, vigorous PA), and moderate to vigorous PA (MVPA: step count > 120/min). BMI z-scores were calculated and regression models were run to examine the relationship between PA and BMI z-scores, adjusting for wear time, sex, and grade. RESULTS: Overweight (38.1%: BMI ≥ 85(th) percentile for age and sex) and obesity (19.4%: BMI ≥ 95(th) percentile) prevalence was similar for boys (n = 782) and girls (n = 700). More MVPA was associated with lower BMI (P < 0.001), independent of sex, wear time or grade. Mean MVPA was 18.9 +/- 8 min/d, versus 15.2 +/- 6.7 min/d for healthy-weight and obese children, respectively. CONCLUSIONS: Children are not meeting minimum MVPA recommendations (60 min/d) during school hours. Efforts to promote PA for obesity prevention in rural elementary schools should focus on increasing opportunities for MVPA.