Patterns of moderate-to-vigorous physical activity (MVPA) among middle-school students by gender and ethnicity

Purpose: Knowledge of youth physical activity (PA) patterns throughout the week is helpful to plan effective PA interventions. The purpose of this study was to determine time spent in moderate-to-vigorous PA (MVPA) across a typical academic week, with specific attention to activity on weekends, weekdays, outside of school, in school (PE, lunchtime, and nonlunch/ PE time), and differences by gender and ethnicity.

Methods: Non-athlete sixth grade students (N=109; age=11.06[0.44]; BMI%ile=66.79[31.04]; 50% male; 50% Latino, 14% African American, 17% non-Hispanic White). Actigraph accelerometers (≥3 valid week days, ≥1 valid weekend day; Romanzini (2012) cutpoints; triaxial; 15 sec epochs) were used to determine time in MVPA.

Results: Average MVPA was greater on weekdays compared to weekend days (84 vs. 72 min, p<0.001). Of weekday MVPA, a greater quantity was accrued outside of school compared to during school (48 vs. 36 min, p<0.001). Lunchtime and PE provided 17% and 37% of total school MVPA. Girls engaged in fewer minutes of MVPA compared to boys across all segments of the day (ps<0.005) except for non-lunch/PE time. African Americans engaged in greater MVPA compared to other ethnicities, particularly on weekends (p<0.005).

Conclusions: Regardless of gender and ethnicity, participants obtained recommended levels of MVPA (>60 min per day), suggesting that maintenance should be the focus of PA interventions in sixth grade students. This study supports the well-characterized gender and ethnic disparity in MVPA. Future research should identify sources of weekday MVPA not accounted for by PE and lunchtime, since these amounts were substantial.