FeaturesScientific Rationale for RPE Use in Fitness Assessment and Exercise ParticipationKilpatrick, Marcus Ph.D., FACSM; Newsome, A’Naja M.S.; Foster, Carl Ph.D., FACSM; Robertson, Robert Ph.D., FACSM; Green, Matt Ph.D., FACSMAuthor Information Marcus Kilpatrick, Ph.D., FACSM, is a professor of Exercise Science in the College of Education, University of South Florida. His research interests include perceptual aspects of exercise, including mood, enjoyment, and perceived exertion, exercise motivation, and high-intensity interval training. A’Naja Newsome, M.S., is the assistant director of Fitness in Campus Recreation and a doctoral student at the University of South Florida. Her research interests include the psychosocial determinants of exercise, perceptual aspects of exercise such as motivation and adherence, and methodological and measurement aspects of exercise program evaluation. Carl Foster, Ph.D., FACSM, is a professor of Exercise Science in the Department of Exercise and Sport Science, University of Wisconsin–La Crosse. His research interests include training monitoring, assessment of exercise responses during exercise testing and training, and practical aspects of exercise performance such as pacing strategy. Robert Robertson, Ph.D., FACSM, is professor emeritus in the Department of Health and Physical Activity, University of Pittsburgh. His research interests include perceived exertion measurement and applications across populations ranging from clinical patients to high level athletes. Matt Green, Ph.D., FACSM, is a professor of Exercise Science in the Department of Kinesiology and associate dean in the College of Education at the University of North Alabama. His research interests include exercise evaluation, perceptual models, thermoregulation, ergogenic aids, and recovery. ACSM's Health & Fitness Journal: 7/8 2020 - Volume 24 - Issue 4 - p 24-30 doi: 10.1249/FIT.0000000000000587 Buy Metrics AbstractIn Brief Apply It! • Fitness professionals will learn the different ways that RPE scales can be used. • Fitness professionals will have newfound confidence in the importance of regulating exercise by using RPE scales. • Fitness professionals will be able to properly use RPE scales during exercise testing and prescription. Ratings of perceived exertion (RPEs) have a long history of use in the world of fitness. The effective use of these tools by clinicians and practitioners can optimize patient and client outcomes. Copyright © 2020 by American College of Sports Medicine.