Psychobiology and Behavioral Sciences Validation of the Children’s OMNI RPE Scale for Stepping Exercise ROBERT J. ROBERTSON, FREDRIC L. GOSS, JOSEPH L. ANDREACCI, JOHN J. DUBE ´ , JASON J. RUTKOWSKI, BROOKE M. SNEE, RUTH A. KOWALLIS, KIM CRAWFORD, DEBORAH J. AARON, and KENNETH F. METZ Center for Exercise and Health-Fitness Research, University of Pittsburgh, Pittsburgh, PA ABSTRACT ROBERTSON, R., F. GOSS, J. ANDREACCI, J. DUBE ´ , J. RUTKOWSKI, B. SNEE, R. KOWALLIS, K. CRAWFORD, D. AARON, and K. METZ. Validation of the Children’s OMNI RPE Scale for Stepping Exercise. Med. Sci. Sports Exerc., Vol. 37, No. 2, pp. 290 –298, 2005. Purpose: The stepping pictorial format of the Children’s OMNI Perceived Exertion Scale (0 –10) was validated for female (N = 20) and male (N = 20) children, 8 –12 yr old with a peak (step) oxygen consumption of 46.1  5.3 mL·kg -1 ·min -1 . Methods: Ratings of perceived exertion for the overall body (RPE-O), legs (RPE-L), and chest (RPE-C) were determined by the OMNI-Step Scale. Concurrent scale validity was examined by regressing OMNI-Step RPE against oxygen consumption (V ˙ O 2 ; mL·kg -1 ·min -1 ) and heart rate (HR, beats·min -1 ). Construct scale validity was examined by regressing OMNI-Step RPE (i.e., conditional metric) against OMNI-Cycle RPE (i.e., criterion metric). Variables were measured at the end of each 2-min stage during load-incremented step and cycle exercise. Results: The range of responses over the test stages for the combined female and male sample was V ˙ O 2 : 9.1–38.6 mL·kg -1 ·min -1 ; HR: 88.0 –168.2 beats·min -1 ; and RPE-O, RPE-L, and RPE-C: 1.0 –9.1. Using concurrent regression models, RPE-O, RPE-L, and RPE-C distributed as positive linear functions of both V ˙ O 2 and HR (r = 0.81– 0.94 P  0.05). Construct regression models indicated a strong linear function between OMNI-Step and OMNI-Cycle RPE for females and males. Differences in RPE (O, L, and C) were not found when females and males used pictorials depicting the same or opposite gender. RPE-L was higher (P  0.05) than RPE-C at all test stages. Conclusion: Responses established concurrent and construct validity of the Children’s OMNI-Step Scale over a wide intensity range. The OMNI-Step Scale is not influenced by pictorials’ gender and is effective in assessing both undifferentiated and differentiated RPE in young children. Key Words: CONCURRENT AND CONSTRUCT VALIDITY, OXYGEN CONSUMPTION, HEART RATE, CHILDREN, STEP ERGOMETRY T his investigation examined concurrent and construct validity of the stepping format for the Children’s OMNI Perceived Exertion Scale, that is, the OMNI- Step Scale (Fig. 1). The concurrent validation paradigm determined whether ratings of perceived exertion (RPE) derived from the OMNI-Step Scale changed as a function of concurrent changes in physiological responses during a load-incremented stepping protocol. The construct para- digm determined whether the OMNI-Step Scale measures the same perceived exertion construct as does the previously validated Children’s OMNI-Cycle Scale (15). The term OMNI is a contraction of the word omnibus and refers to a numerical category scale that employs interchangeable sets of mode-specific pictorial descriptors positioned along a visually discernible exertional intensity gradient. As such, the OMNI Scale pictorial format is generalizable across a broad range of weight-bearing and nonweight-bearing ex- ercise modes. Previous investigations have established concurrent validity of the cycle and walk/run formats of the Children’s OMNI Scale. Validity coefficients between RPE and both oxygen consumption (V ˙ O 2 ) and heart rate (HR) ranged from r = 0.41 to r = 0.94 during progressively incremented cycle ergometer (15) and treadmill exercise (22). However, neither concurrent nor construct validity evidence is available for the step format of the Children’s OMNI Scale, leading to the primary purpose of this investigation. In addition, a number of previous inves- tigations have demonstrated that children (8 –12 yr old) can use the cycle format of the OMNI Scale to differentially rate the intensity of the peripheral perceptual signal arising from the legs and the intensity of the respiratory-metabolic perceptual signal arising from the chest (15,17). Similar validity evidence regarding differentiated measurement properties of the step format for the Children’s OMNI Scale is not available. There- fore, validity of the OMNI-Step Scale was examined using differentiated RPE for the legs (RPE-Legs) and chest (RPE- Chest) as well as the undifferentiated RPE for the overall body (RPE-Overall). Address for correspondence: Robert J. Robertson, Ph.D., 140 Trees Hall, University of Pittsburgh, Pittsburgh, PA 15261; E-mail: rrobert@pitt.edu. Submitted for publication July 2004. Accepted for publication October 2004. 0195-9131/05/3702-0290 MEDICINE & SCIENCE IN SPORTS & EXERCISE ® Copyright © 2005 by the American College of Sports Medicine DOI: 10.1249/01.MSS.0000149888.39928.9F 290