International Journal of Exercise Science 10(8): 1130-1144, 2017. The present investigation examined the Adult OMNI Walk-Run Scale for use by an independent observer to rate an individual’s perception of exertion during intermittent treadmill walking and running. Forty (22.4 ± 2.9 yrs) recreationally active males (n = 18) and females (n = 22) completed three 5-min intermittent bouts of treadmill exercise. The exercise bouts were a level walk (LW; 4.0 km∙hr-1, 0% grade), hill walk (HW; 5.6 km∙hr-1, 5% grade), and run (R; 8 km∙hr-1, 2.5% grade). Each bout was separated by a 5-min recovery period. RPE responses were simultaneously estimated by an observer and self-estimated by the participant during each bout using the Adult OMNI Walk-Run Scale. Session RPE responses were simultaneously estimated by the same observer and self-estimated by the participant 5-min post-exercise session. Analysis of variance indicated no significant mean differences between observer RPE and participant RPE (p \u3e 0.05) except for males during the running bout (p \u3c 0.05). Additionally, there were no significant mean differences between the observer RPE and the participant RPE for the session ratings (p \u3e 0.05). Finally, strong positive correlations were found between observer and participant RPE ranging from 0.79-0.84 for exercise bouts and moderate-strong positive correlations ranging from 0.58-0.64 for the exercise session. Results support the use of the OMNI RPE Scale in a direct observation procedure to estimate exertion in female and male young adults performing intermittent treadmill walking and running. This observation-based procedure provides the practitioner with an opportunity to independently evaluate the perceptual intensity of individuals involved in aerobic exercise
