A study on acute expectation effects on affective state and intention after a brief full-body workout in a student sample.

Brief exercise bouts can have positive effects on the affective state, which in turn could affect the intention for future exercise. Such benefits may be enhanced by manipulating expectations. The aim of this study was to examine whether the affective state after physical activity or the intention for future exercise can be influenced by manipulating expectations. Furthermore, the relationship between affect and intention was investigated. In an online experiment, 121 persons completed either a 10-minute workout (PA), a workout after manipulation of expectations (PA + EM), or a control intervention (CG) after randomized group allocation. Data on affective state, expectations, and intention were collected before and after the intervention using questionnaires. After intervention, PA groups showed significantly more positive values than CG in several affective parameters, in other affective parameters, only PA + EM differed from CG. Affect was positively associated with intention alongside outcome expectations. No difference was found in intention. Although no significant effects of expectation manipulation on affective state or intention were found, latent effects cannot be ruled out. Further exploration of the importance of word choice in describing physical activity in the context of interventions to increase physical activity is necessary. Here, affect should be considered.