Variation and homogeneity in affective responses to physical activity of varying intensities: An alternative perspective on dose – response based on evolutionary considerations

Abstract

A model for systematic changes in patterns of inter-individual variation in affective responses to physical activity of varying intensities is presented, as a conceptual alternative to the search for a global dose – response curve. It is theorized that trends towards universality will emerge in response to activities that are either generally adaptive, such as moderate walking, or generally maladaptive, such as strenuous running that requires anaerobic metabolism and precludes the maintenance of a physiological steady state. At the former intensity the dominant response will be pleasure, whereas at the latter intensity the dominant response will be displeasure. In contrast, affective responses will be highly variable, involving pleasure or displeasure, when the intensity of physical activity approximates the transition from aerobic to anaerobic metabolism, since activity performed at this intensity entails a trade-off between benefits and risks. Preliminary evidence in support of this model is presented, based on a reanalysis of data from a series of studies.

Keywords:

• Affect
• displeasure
• homogeneity
• inter-individual variability
• pleasure

Acknowledgements

We wish to thank Professor Michel Cabanac (Département de Physiologie, Faculté de Médecine, Université Laval, Québec, Canada) for his pioneering insights into the adaptational bases of the affective responses to physical activity, his encouragement, and his numerous suggestions on two earlier drafts of this manuscript. We also wish to thank Dr Elizabeth Queathem (Department of Biology, Grinnell College), Dr Joey C. Eisenmann (Department of Health and Human Performance, Iowa State University), the psychology section editor Professor Nanette Mutrie and the three anonymous reviewers for their critical and very constructive comments.