Background and purpose: The measurement of affect in the context of exercise is a controversial issue. The purpose of this paper is to provide a critical review of the relevant literature and to outline a conceptual framework that will serve as the basis for subsequent analysis.Methods: Four issues are discussed: (a) the distinctions between emotions, moods, and affect; (b) the strengths and weaknesses of categorical and dimensional models for conceptualizing affective phenomena; (c) the notion of 'exercise-specific' affect; and (d) whether measurement should be based on a deductive or an inductive approach.Results and conclusions: Arguments are presented in favor of (a) targeting basic affect as the appropriate object of assessment at the present stage of knowledge development; (b) adopting dimensional models because of their broad and balanced scope; (c) critically reconsidering the notion of 'exercise-specific' affect; and (d) using deductive methods for measuring affect.