Abstract
BACKGROUND: Daily decisions to exercise may be influenced by day-to-day changes in affective attitudes (AA) and instrumental attitudes (IA) toward exercise. However, the within-day association between AA, IA, and exercise behavior has received little attention. PURPOSE: To examine the effects of more temporally proximal (daily) AA and IA on daily exercise behavior beyond traditionally assessed distal (at the beginning of an exercise program) AA and IA. METHODS: In the context of a 3-month exercise promotion program (N = 50), distal AA and IA were assessed at baseline. Ecological momentary assessment was used to assess proximal AA, IA, and exercise each day. RESULTS: Between-subject differences in distal AA (OR = 1.28, p = .03) and distal IA (OR = 1.34, p = .01) were predictive of average likelihood of exercise each day over the 3-month period. Within-subject differences in proximal AA (OR = 1.19, p = .007), but not proximal IA (OR = 1.11, p = .18), predicted exercise each day beyond the between-subjects effects of distal AA and IA. Exploratory analysis revealed an interaction, such that the within-subjects impact of proximal AA on daily exercise was most evident among individuals who held more negative distal AA at baseline (OR = 0.80, p < .0001). CONCLUSIONS: Attitude type (affective versus instrumental) and temporality (distal versus proximal) are important to consider in attempts to predict and understand exercise behavior. In addition to targeting change in distal attitudes, exercise interventions should target changes in daily AA to impact exercise later in the same day.