The purpose of this project was to examine the effectiveness of a fitness infusion instructional strategy (FI) on children's activity levels and skill performance scores. This strategy included aerobic activity within the skill practice tasks and game play. In other words, students performed short bouts of activity between the practice and game/application trials. Participants were 86 fifth-grade students who participated in six activities over a 24-week period. The six activities were tennis skills, gymnastics, volleyball skills, floor hockey skills, basketball skills, and softball skills. Results indicated that both the control group and the FI group showed significant gains in skill performance scores from pre to posttest. The primary finding, however, was that the FI group exhibited heart rates that more than doubled those of the control group. These results suggest that infusing fitness into the skill practice and game play does not have a negative impact on skill development. In light of the alarming increase in obesity rates among children and adolescents, these preliminary findings may provide a practical strategy to increase physical activity levels and improve motor skills during physical education class. (Contains 2 tables and 1 figure.)