The perception of effort is multidimensional and it is governed by many physiological, psychological, and experiential factors. This paper deals with a discussion of selected psychological states and traits that are known to be correlated with the expression of effort sense. It has been shown that anxiety, somatic perception, depression, and neuroticism are associated with perceived exertion. Extroversion has been found to be inversely correlated with perceived exertion, and positively correlated with preferred exercise intensity. These empirical findings are congruent with theoretical expectations in each case. It has also been found that perception of effort can be increased and decreased in a systematic manner with various psychological interventions such as hypnotic suggestion, dissociative cognitive strategies, and imagery. Changes in effort sense can also be systematically modified by titrating exercise volume (e.g., overtraining, tapering), and this exercise-induced alteration in perception covaries with affective changes. The research reviewed in this paper supports the conclusion that effort sense is best conceptualized as a complex psychobiological construct as originally proposed by Borg three decades ago.