Estimated Energy Expenditure during Classroom-Based Physical Activity

Context Classroom-based physical activity (CBPA) provides an important opportunity to improve student health but is underutilized. Advocating for CBPA requires informing stakeholders about the benefits, including energy expenditure, in comprehensible terms. Objective To compare energy expenditure in kcal for elementary school CBPA with energy expenditure values for physical education and recess. Design Using break/lesson duration and physical activity outcome data reported in eligible observational and interventional CBPA studies, we calculated potential energy expenditure using the following formula: energy cost (kcal) = MET y × BMR (kcal·min −1 ) × duration, where MET y is intensity in metabolic equivalents of task and BMR is basal metabolic rate. Eligibility Criteria Studies included in the energy expenditure calculations had to 1) be conducted among elementary school students in a classroom-based setting: 2) report objective measures of physical activity intensity: and 3) report minutes in moderate-to-vigorous physical activity (MVPA), percentage of time in MVPA, MET-minutes, units that could be converted to MVPA or energy expenditure, or energy expenditure (kcal) directly. Study Selection We reviewed the 111 nonduplicated primary research studies included in the analyses of the eight most recently published (through 2022) reviews of CBPA. Of those, 41 met the eligibility criteria and were used to calculate energy expenditure. Main Outcome Measure Potential energy expenditure in kcal during a standardized 20-min CBPA break/lesson. Results Average break/lesson duration was 11.0 ± 16.2 min, and 10-min breaks/lessons ( n = 16, 39%) were most common. The mean energy expenditure calculated across the 41 studies was 67.47 ± 19.06 kcal per 20-min session. Conclusion Potential energy expenditure from elementary CBPA is commensurate with values calculated for both physical education and recess, further highlighting the value of CBPA as an opportunity for increasing student energy expenditure. These findings should be incorporated into advocacy strategies to effect policy change and implementation at distal (i.e., state policy) and proximal (i.e., school policy) levels.