Executive Functioning and Explicit Physical Activity Self-Regulation Associated with the Activity Choice Index

The Activity Choice Index (ACI) has been designed to account for transient moments in one’s daily life and the extent to which effortful decisions to choose physically active tasks are made. It has only been validated in Portuguese samples and little is known about the extent to which choices are associated with executive functioning (EF) and explicit (physical activity self-beliefs) vs. implicit motives. The purpose of this study was to validate the ACI in a U.S. sample of middle-aged adults and to test theorized mechanisms underlying the activity choices targeted by the ACI. Data from this study were derived from 133 middle-aged adults (Mage = 53.82; 79% women; BMI = 32.06) who were randomized to 20 hours of supervised cognitive-motor training or attention control (video) interventions. Participants completed baseline (M0) and post-intervention testing at Month 1 (M1), including 7-day Fitbit monitoring and self-report measures of physical activity, self-regulation strategies, self-efficacy, explicit and implicit attitudes, and cognitive assessments (e.g., dual task). Pre-intervention ACI was not collected (true M0), and no group differences were found, so M1 associations were analyzed with the collapsed sample. Bivariate correlations were low but statistically significant (p < .05) between ACI and M0 and M1 Fitbit steps and self-reported physical activity. Self-regulation strategies (r’s = .46, .40), future self-identity (r’s = .39, .31), and exercise self-efficacy (r’s = .21, .27) were also positively associated with ACI. Interestingly, implicit attitudes were not associated with ACI and negative correlations were found with specific ACI items “park further away” and “standing over sitting” (r’s = -.21, -.30). Dual task correlated only with the “park further away” item at M1 (r = .22). Together, these findings offer support for the theorized role of EF and self-regulation in conscious activity choices and support the ACI’s construct validity and reliability.