Ratings of perceived exertion in individuals with varying fitness levels during walking and running

It was the purpose of this investigation to: 1) compare the ratings of perceived exertion (RPEs) in high and low fit individuals when walking and running at comparable exercise intensities and 2) to determine if ventilation \(\left( {\dot V_E } \right)\) provides a central signal for RPEs. Nine high fit and nine low fit male subjects completed two exercise bouts on a treadmill, one uphill walking and the other level running. Workloads for each bout were set at 90% of each subject's ventilatory threshold (VT) as determined from a graded exercise test. Oxygen consumption \(\left( {\dot V_{O_2 } } \right)\) heart rate (HR), and \(\dot V_E\) were all similar between the walk and run trials for the low fit subjects (P>0.05). HR were found to be significantly greater during the walk trial vs. the run trial (P<0.05) for the high fit subjects, whereas, \(\dot V_E\) was significantly greater during the run trial. Oxygen consumption was similar for the high fit subjects during both trials (P>0.05). During the walk and run trials, central (12.1±.6 vs. 11.4±1.5), local (14.0±1.3 vs. 13.9+1.1) and overall (12.8±1.2 vs. 12.4±1.4) RPEs were not found to be significantly different for the low fit group (P>0.05). In contrast, during the walk vs. the run trial there was a significant increase in central (10.7±2.0 vs. 9.2±1.9), local (11.5±2.0 vs. 9.8±1.8) and overall (11.2±2.4 vs. 9.6±2.3) RPEs for the high fit group (P<0.05). There were significant differences (P0.05) between central and overall RPEs in either the walk or run trial for the low fit group. No significant differences (P> 0.05) were found between the central, local and overall RPEs for either the walk or run trial with the high fit group. Based on the above results, it appears as if walking is perceptually more stressful than running at similar exercise intensities for high fit individuals. Since \(\dot V_E\) was greater for the run trial vs. the walk trial for the high fit subjects, yet RPEs were lower, it does not appear as if \(\dot V_E\) provides a central signal for the determination of RPEs.