Accelerometry and Self-Report Are Congruent for Children's Moderate-to-Vigorous and Higher Intensity Physical Activity.

Purpose: This study used different analytic approaches to compare physical activity (PA) metrics from accelerometers (ACC) and a self-report questionnaire in upper elementary youth participating in the Fuel for Fun intervention. Methods: The PA questionnaire and ACC were assessed at baseline/preintervention (fall fourth grade), Follow-up 1/postintervention (spring fourth grade), and Follow-up 2 (fall fifth grade) of 564 fourth grade students from three elementary schools (50% females, 78% White, and 28% overweight or obese). Different analytic approaches identified similarities and differences between the two methods. Results: On average, self-report was higher than ACC for vigorous PA (range = 9-15 min/day), but lower than ACC for moderate PA (range = 24-30 min/day), light PA (range = 30-36 min/day), and moderate-to-vigorous physical activity (MVPA; range = 9-21 min/day). Spearman's correlations for vigorous PA (.30, .26, and .32); moderate PA (.12, .13, and .14); and MVPA (.25, .25, and .24) were significant at each time point (all ps ≤ .01), whereas correlations for light PA were not significant (.06, .04, and .07; all ps > .05). In repeated-measures analyses, ACC and questionnaire measures were significantly different from each other across the three time points; however, change difference of the two measures over time was only 5.5 MVPA min/day. Conclusions: The PA questionnaire and ACC validated each other and can be used to assess MVPA in upper elementary school children in a similar population to the current study. However, each assessment method captures unique information, especially for light-intensity PA. Multiple PA measurement methods are recommended to be used in research and application to provide a more comprehensive understanding of children's activity. [ABSTRACT FROM AUTHOR]