CONLEY, DOUGLAS L. and GARY S. KRAHENBUHL. Running Economy and distance running performance of highly trained athletes. Med. Sci. Sports Exercise. Vol. 12, No. 5, pp. 357-360, 1980. The purpose of the study was to determine the relationship between running economy and distance running performance in highly trained and experienced distance runners of comparable ability. Oxygen uptake (Vo2) during steady-state and maximal aerobic power (Vo2max) were measured during treadmill running using the open-circuit method. Distance running performance was determined in a nationally prominent 10 km race; all subjects (12 males) placed among the top 19 finishers. The subjects averaged 32.1 min on the 10 km run, 71.7 ml•kg-1•min-1 for Vo2max, and 44.7, 50.3, and 55.9 ml•kg-1•min-1 for steady-state Vo2 at three running paces (241, 268, and 295 m•min-1). The relationship between Vo2max and distance running performance was r = -0.12 (p = 0.35). The relationships between steady-state Vo2 at 241, 268, and 295 m•min-1 and 10 km time were r = 0.83, 0.82, and 0.79 (p<0.01), respectively. Within this elite cluster of finishers, 65.4% of the variation observed in race performance time on the 10 km run could be explained by variation in running economy. It was concluded that among highly trained and experienced runners of comparable ability and similar Vo2max, running economy accounts for a large and significant amount of the variation observed in performance on a 10 km race.