Background: Whereas effects of physical fitness and physical activity on cognitive function have been documented, little is known about how they are related. Purpose: This study assessed student aerobic fitness measured by FITNESSGRAM Mile times and/or Pacer circuits and whether the nature of the association between aerobic fitness and standardized academic performance is dose-response or threshold related. Methods: Standardized academic test scores and aerobic capacity scores were collected from two cohorts of 5th grade students over two years. The Mile run and Pacer circuits results were compared to patterns in students' academic test scores. Results: Sectioning of Mile times and Pacer circuits revealed a sharp peak in academic performance for boys who completed the Mile in 9 minutes or less. Girls' Pacer revealed peaks in academic performance at 12 and 30 circuits. Discussion: Results demonstrate that select achievements in the Mile or Pacer account for significant increases in academic performance on standardized tests. Translation to Health Education Practice: This study identifies aerobic fitness points which, if achieved, offer the greatest probability of increased academic success in fifth graders. Physical education, cross-curricular thematic units, and club activities can be portals of opportunity to increase moderate to vigorous physical activity and fitness in students. Furthermore, school-based physical activity and fitness opportunities may positively impact health risk factors associated with childhood obesity. Policies that increase aerobic activity opportunities in the school setting may increase overall academic performance, encourage positive health habits and improve immediate and future overall health. (Contains 4 tables and 2 figures.)