['To examine the relationship between competitive 800-m and 1500-m performance times and a number of physiological variables in a group of endurance-trained, adolescent runners.', 'Twenty-three boys and 17 girls volunteered to participate in the study. Track-based, running performance times were available for 18 boys and 14 girls for the 800 m, and 16 boys and 13 girls for the 1500 m. The relationships between these times and the following physiological variables were determined: peak VO(2) running economy (RE), estimated running speed at peak vV0(2peak), peak and mean anaerobic power, and fixed [BLa ] at 2.0, 2.5, and 4.0 mmol.L.', "RE and vV0(2peak) were significant independent variables for the boys' 800 m (r = 0.62 and -0.62, < 0.01). For the girls, once chronological age was partialled out, none of the measured variables were significantly related to 800-m performance. For the 1500-m event, peak V0(2), vV0(2peak), and the running speed at 2.5 mmol.L (v2.5) were significant independent variables in the boys (r = -0.43, -0.39, and -0.53, < 0.05) and girls (r = -0.50, -0.61, and -0.54, < 0.05). In addition, the V0(2) at 2.5 mmol.L V0(2) (2.5) was related to the 1500-m time in the girls (r = -0.54, < 0.05)."] Does physiological correlate with endurance running performance in trained adolescents?