Is a Cup Enough? Levels of Energy Expenditure During Speed Stacking

This study evaluated whether Speed Stacking elicits sufficient physiological intensity to meet moderate-to-vigorous physical activity (MVPA) thresholds in youth, using portable indirect calorimetry and accelerometry. Fifty-four participants (<i>M</i>age = 14.01 ± 5.48 years; 46.3% female) completed four randomized activity conditions: Rest, Speed Stacking, Running, and Speed Stack + Run, each lasting five minutes. Participants wore a COSMED K5 metabolic system, hip and wrist ActiGraph GT3X+ accelerometers, and a heart rate monitor. Energy expenditure (METs), accelerometer counts, perceived exertion, and fun were analyzed using repeated measures ANOVAs and Cohen's Kappa for method agreement. In both prepubescent and pubescent groups, Speed Stacking alone did not meet the specific MET thresholds for MVPA. However, the hybrid Stack + Run condition significantly increased METs (up to 5.1 ± 1.2 in prepubescents). Cohen's Kappa revealed poor agreement between MET-based and accelerometer-based intensity categorical classifications across all conditions. Participants, especially younger children, reported Speed Stacking as fun but minimally effortful. Speed Stacking alone fails to meet key pedagogical criteria for physical education, particularly those related to maximizing activity time and MVPA engagement. Given the limited time available in PE settings, alternative activities with higher energy expenditure may offer a more efficient use of instructional time. However, when integrated with movement-based tasks, Speed Stacking can be adapted to better support physical and educational outcomes.