UC Irvine

The present study tests the hypothesis (derived from Competence Motivation Theory (CMT)) that affective response to exercise mediates the link between perceived competence for exercise and Physical Activity (PA). The relationship between affect and PA behavior likely depends on affective style, a trait that determines individuals' affective responsivity to emotion-eliciting stimuli. Therefore, the link between affect and PA was hypothesized to be moderated by affective style.

Healthy sixth grade students completed a perceived competence and an affective style (BIS/BAS scale) questionnaire, wore an Actigraph accelerometer to measure MVPA, and performed 30-minute exercise tasks on a cycle ergometer: (a) a moderate-intensity exercise task, and (b) a "feels-good" task during which they were encouraged to maintain an intensity that felt good (30 min). Outcome variables were (a) work rate, heart rate and rating of perceived exertion (RPE) as indicators of exercise intensity during the feels-good task, and (b) MVPA throughout the day and during PE. Affect was measured every three minutes during the moderate exercise task; mean and lowest affect were used in analyses.

Partial support for CMT was found. Affect mediated the association between competence and self-selected intensity. Competence was positively associated with MVPA, but affect did not mediate this relationship. The behavioral activation system (BAS) moderated the association between affect and RPE such that the link between affect and RPE was strongly attenuated in individuals with less sensitive BAS. The BAS also moderated the association between affect and MVPA such that individuals with less sensitive BAS had a positive association between affect and MVPA whereas those with more sensitive BAS had a negative association between affect and MVPA.

The results suggest that the link between competence, affect, and exercise may be more complex than proposed. Interventions that are tailored to maximize competence may result in greater enjoyment and PA engagement. The differential association of affect and exercise across levels of BAS suggests that further investigation into the dynamics of affective style in relation to exercise may yield personalized approaches to promote PA. Integrating ecological assessment into research may lead to discoveries that will improve personalized interventions for PA promotion.