The purpose of this study was to compare the metabolic (VO2) and cardiovascular (HR) responses between downhill and level running at the same perceived exertion (RPE) levels. Subjects included 10 trained male runners from the Slippery Rock University Track Team (M age=21 + 4 yrs). Subjects performed two bouts of submaximal running on two separate occasions. In the first session, either a level or a downhill (-10 deg) treadmill run was performed (counterbalanced). The initial treadmill speed was set at 2.0 mph and was increased .5 mph each minute. VO2, RPE and HR were recorded during the last 10 s of each min. Twenty-four to forty-eight hours later, subjects ran using the same treadmill protocol under the alternate condition. HR and VO2 were then compared between the two trials at RPE values 10, 12, and 14 (Borg 15-Category Scale). A two-way ANOVA for repeated measures was used to evaluate the differences between the level and downhill grades. No significant differences (p<.05) were revealed for either HR or VO2 at any RPE between the two conditions. However, there were trends toward lower HR (106-145 b/min vs. 119-156 b/min) and VO2 (18-35 ml/kg/min vs. 22-41 ml/kg/min) in the downhill condition, indicating a tendency to rate the downhill bout as more strenuous for a given metabolic/cardiovascular demand. Additional research will be necessary to further probe the relationship between perceptions of effort and eccentric exercise in the form of downhill running.