running economy (re) is an important predictor of endurance performance. to date, the typical methods of measuring re involves calculating an athlete’s vo2 (ml-1·kg−1·km−1) at a known speed during a physiological steady-state. measuring re for athletes who race at distances above the anaerobic threshold (at) (800m – 5000m) is problematic because these distances are contested in conditions when physiological steady-states cannot be achieved. the current study explored the use of excess post-exercise oxygen consumption (epoc) being added to the oxygen consumption during running for estimating re above the at and examined the construct validity of this measurement technique. the epoc was measured for three minutes (fast component) from seven male and seven female varsity cross-country runners after running for three minutes at a pace of 1.0 mile per hour (mph) above their calculated at pace. construct validity was established by noting theoretical associations and computing pearson product-moment correlation coefficients between blood lactate (bla), heart rate (hr), ventilation (ve), and excess co2, and re. for the male participants, excess co2 had the highest correlation (r = .629, p < .005), followed by bla (r = .586, p < .001). in the female participants ventilation had the strongest correlation (r = .836, p < .001) followed by excess co2 (r = .607, p <.001). these results support the construct validity for our measurement technique. the findings from this study will have implications as a performance assessment tool for researchers, coaches, and athletes.