Purpose. To assess physical activity levels during active video game play over time and compare this to ‘free play’ associated with recess activity in a sample of British primary school children over a 6-week period. Basic procedures. Thirty children (ages 10-11, 12 boys, 18 girls) from central England were randomly selected to participate in a 6 week, recess based, active video gaming intervention (n = 15) or act as controls (n = 15). Repeated measures analysis of covariance (controlling for body fatness) was used to examine any differences in physical activity, determined by pedometry and heart rate monitoring over time and between intervention and control groups. Main Findings. Children in the intervention accumulated significantly greater steps/day than the control group during the first week of the intervention. This pattern was reversed at the mid and end points of the intervention (p = .03). Irrespective of time point, children engaging in active video game play spent a lesser percentage of time engaged in MVPA than the controls undertaking ‘traditional’ recess activity (p = .0001). Conclusions. Active video game play does not appear to be a sustainable means to enhance children's physical activity. Although physical activity (steps/min) was greater on initial presentation of active video games compared to ‘traditional’ recess activity, this appears to be an acute effect.