UC Irvine

Physical inactivity is a major public health concern that has not been adequately addressed by social-cognitive behavioral theories and models. Recent research has identified affective responses to acute exercise as a promising but often overlooked factor related to individuals' physical activity behavior. Affective responses have been associated with physical activity cross-sectionally and prospectively. Associations of exercise-related affective responses with physiological and behavioral markers of approach motivation suggest that affective responses to exercise may represent an affective style or underlying predisposition to enjoy physical activity that distinguishes regular exercisers from non-exercisers; however, this hypothesis has not been directly explored. The present dissertation reports on two studies that examined whether acute affective responses to exercise reflect an affective style. Chapter 2 describes a study that examined the consistency of adolescents' affective responses across exercise intensity and setting, and the stability of adolescents' affective responses to exercise over time. Operating under the assumption that there are individual differences in the extent to which acute responses reflect global traits, this study further examined whether individual differences in the degree of affective response consistency play a role in predicting future physical activity behavior. The results suggest that affective responses to acute exercise are consistent across exercise intensity. A substantial proportion of participants failed to complete exercise tasks in a free-living setting, and the study therefore was not a strong test of the hypotheses involving free-living exercise. The results did not provide evidence of affective response consistency across exercise setting or of affective response stability over time, likely owing to the number of missing cases. Findings regarding the role of consistency in the affective response- PA relationship were inconclusive. Chapter 3 describes a study that examined the stability of affective responses over time to a standardized clinic-based exercise task. The results suggest that, when examined across tasks of the same intensity and in the same setting, affective responses are stable. The findings provide support for the notion that affective responses to acute exercise can be conceptualized as a relatively stable, trait-like characteristic that may help to identify adolescents at increased risk for a sedentary lifestyle.