RATINGS OF PERCEIVED EXERTION
Following two decades of research, Gunnar Borg’s original rating of perceived exertion (RPE) scale was accepted in 1973 as a valid tool within the field of exercise science and sports medicine (Noble and Robertson, 1996). His seminal research provided the basic tool for numerous studies in which an individual’s effort perception was of interest. It also provided the basis and incentive for the development of other scales, particularly those used with children. Borg’s initial research validated the scale against heart rate and oxygen uptake. Later research focussed on the curvilinear growth of perceived exertion with lactate, ventilation and muscle pain responses, and led to the development of the category-ratio (CR-10) scale.