Traditional conceptions of the exercise–affect relationship postulate that moderate-intensity exercise leads to positive affective changes in all or most individuals, and it can, therefore, be prescribed for all individuals involved in exercise programs. This study investigated whether this assumption is true, not only at the level of group averages but also at the level of individuals. Affect was assessed before, during, and after a session of moderate-intensity cycle ergometry using a dimensional conceptualization of affect. Examination of individual responses revealed a diversity of patterns that was masked by aggregate-based analyses. Mean ratings of affective valence were shown to remain stable during exercise, but in actuality almost half of the individuals experienced progressive improvement, whereas the other half experienced progressive deterioration. The diversity of individual affective responses must be taken into account in formulating conceptual models of the exercise–affect relationship and deriving public health physical activity recommendations.
Address correspondence to Steven J. Petruzzello, Department of Kinesiology, University of Illinois at Urbana-Champaign, Urbana, IL 61801.