Background: After-school programs (ASPs) have the potential to contribute to student physical activity (PA), but there is limited empirical evidence to guide program development and implementation. Methods: We used pedometry to assess the overall effectiveness of an elementary school ASP running program relative to national and state PA recommendations and to compare 2 different formats (laps vs games) on PA and energy expenditure. Results: Both running laps and running games contributed substantially to PA accrual and energy expenditure (overall 24.2 minutes of PA and 52.6 kcal during sessions averaging 37 minutes), but the formats provided different outcomes relative to PA intensity and energy expenditure. Overall PA% was higher on lap days, but MVPA% (moderate-to-vigorous PA) was higher on game days. Only game days met the stipulation that ASPs provide activities at an intensity in which MVPA% of PA = 50%. Conclusions: Both running laps and running games in an ASP can contribute to PA accrual. ASP providers should weigh the demands and outcomes of program activities, and especially consider the quality of activities, students' feelings about them, and the implementation demands on instructors.