Perceived Exertion during Exercise with Concentric and Eccentric Muscle Contractions

Abstract

The perception of exertion was studied with special reference to oxygen consumption anil heart rate under two exercise conditions, namely with concentric (shortening) and eccentric (lengthening) muscle contractions. Exercise was performed on a Krogh cycle ergomoter adapted for the two types of exercise. Oxygen consumption was determined by Douglas bag-Haldane toehniquo, heart rate by ECG, and perceived exertion by a rating scale. Eccentric exercise was perceived as requiring less exertion compared to concentric exercise at similar intensities. When compared on the basis of equal oxygen consumption and heart rate, eccentric exercise was perceived as requiring greater exertion. Exercise at lower rpm was perceived as requiring greater exertion in both forms of exercise as opposed to exercise at higher rpm. It is suggested that exertion during various forms of exercise and under different conditions is perceived or assessed from differonfc combinations of information obtained from afferent and efferent signals.