Excerpt: > Despite the ubiquitous media message that “exercise feels good,” it is now clear that the relationship between exercise and affect is not so simple

Excerpt: > Despite the ubiquitous media message that “exercise feels good,” it is now clear that the relationship between exercise and affect is not so simple (Emerson and Williams, 2015). While most people tend to feel good after exercise, many people—including a large proportion of inactive and unfit individuals who are the targets of physical activity (PA) promotion efforts—feel bad during exercise (Ekkekakis et al., 2011). Thus, from a public health perspective, it is critically important to understand why many people have a negative affective response to a behavior—physical exercise—that is good for their health. That is, why do many people dislike exercising? The aim of this paper is to attempt to answer this question by taking an evolutionary perspective. We will argue that the negative affective response to exercise is a manifestation of an evolved tendency to avoid energy expenditure that served no immediate adaptive function. In modern environments, this evolved psychological mechanism has led to difficulty with exercise adherence and overall low rates of PA.