The influence of sensory cues on the perception of exertion during exercise and central regulation of exercise performance

The perception of effort during exercise and its relationship to fatigue is still not well understood. Although several scales have been developed to quantify exertion Borg's 15-point ratings of perceived exertion (RPE) scale has been adopted as a valid and reliable instrument for evaluating whole b ody exertion during exercise. However, Borg's category-ratio scale is usefu l in quantifying sensations of exertion related to those variables that ris e exponentially with increases in exercise intensity. Previous research has examined the extent to which afferent feedback arising from cardiopulmonar y and peripheral variables mediates the perception of exertion. However, the literature has not identified a single variable that consisten tly explains exertion ratings. It is concluded that effort perception invol ves the integration of multiple afferent signals from a variety of perceptu al cues, In a process defined as teleoanticipation, the changes in perceive d exertion that result from these afferent signals may allow exercise perfo rmance to be precisely regulated such that a task can be completed within t he biomechanical and metabolic limits of the body. The accuracy with which individuals can regulate exercise intensity based upon RPE values, the decr ease in muscle recruitment (central drive) that occurs before fatigue, and the extent to which perceived exertion and heart rate can be altered with h ypnosis and biofeedback training all provide evidence for the existence of such a regulatory system. Future research is needed to precisely quantify t he extent to which efferent feedforward commands and afferent feedback dete rmine pacing strategies such that an exercise event can be completed withou t irreversible tissue damage.