Purpose: The purpose of this study was to comparatively evaluate the use of heart rate (HR) or rating of perceived exertion (RPE) in eliminating the slow component of oxygen uptake (VO2) during high-intensity aerobic exercise. Methods: Nine sedentary males (age = 23.9 +/- 4.6 yr, height = 177.4 +/- 10.1 cm, weight = 75.28 = 12.95 kg) completed three 15-min submaximal exercise cycle ergometer tests based on: 1) constant Power output (PO) corresponding to 75% VO2max (PO75), 2) HR corresponding with 75% VO2max (HR75), and 3) RPE response corresponding with 75% VO2max (RPE75), VO2, HR, RPE, and blood lactate concentration [La-] were measured during all tests. Data were analyzed using repeated measures analysis of variance, and post hoc means comparisons were performed using a Fisher's LSD test. Results: End-exercise VO2, was significantly higher than the respective 3-min VO2, for the PO75, and RPE75 tests. but not the HR75, test. End-exercise VO2, was significantly greater for the PO75, test than both the RPE75 and HR75 tests. but there was no significant difference between end-exercise VO2, for the RPE75 and HR75 tests. End-exercise FIR and RPE were significantly higher for the PO75 test than both the RPE75, and HR75. tests. There were no significant differences between the RPE75 and HR75 tests for end-exercise HR or end-exercise RPE. Conclusion: Results suggest using both HR and RPE are effective at reducing the slow component of VO2, that occurs during high-intensity exercise.