<Evolution of perceived exertion concepts and mechanisms: a literature review>

The mechanisms and concepts of perceived exertion have changed over the years. Thus, the objectives of the present literature review were i) to investigate the literature reviews that have been published since 1982 and to describe the proposed causal mechanisms of perceived exertion, and ii) to determine whether the concepts of perceived exertion have accompanied the changes of its proposed mechanisms. Searches were per-formed in PubMed, Science Direct and Scielo using the terms ‘rating of perceived exertion and review’ and ‘perceived exertion and review’. Eighteen papers whose main objective was to determine the overall perceived exertion during physical exercise were included in the present study. It was observed that, despite the existence of the early corollary discharge theory, after Borg’s propositions most of the literature has explained perceived exertion using the afferent feedback theory based on correlational studies. It was only in 2009 that there was a resurgence of the original corollary discharge theory in perceived exertion papers. Most of the perceived exertion concepts are related to the afferent feedback mechanism, using constructs such as physiological responses, stress, discomfort and pain. However, these constructs are incongruent with the corollary discharge theory, presenting physiological mechanisms that differ from those of perceived exertion. Therefore, Borg’s studies have influenced contemporary views of the mechanisms and concepts of perceived exertion. Over the years, additional constructs have been incorporated into the original Borg’s concept, although always on the basis of the afferent feedback theory