Exercise makes people feel better but people are inactive: paradox or artifact?

The exercise psychology literature includes an intriguing, albeit not frequently discussed, paradox by juxtaposing two conclusions: (a) that exercise makes most people feel better and (b) that most people are physically inactive or inadequately active. In this article, we propose that this might be an artifact rather than a paradox. Specifically, we question the generality of the conclusion that exercise makes people feel better by proposing that (a) occasional findings of negative affective changes tend to be discounted, (b) potentially relevant negative affective states are not always measured, (c) examining changes from pre- to postexercise could miss negative changes during exercise, and (d) analyzing changes only at the level of group aggregates might conceal divergent patterns at the level of individuals or subgroups.