Brain network predictors of exercise behavior change in sedentary older adults

Abstract

Given the proliferating aging population, increasing moderate-to-vigorous physical activity (MVPA) and exercise is critical because it enhances overall well-being and reduces the rates of many adverse age-related health conditions. However, intervention efforts to establish sustained changes in MVPA have yielded limited success due their sole focus on conscious factors (e.g., changing goals and intentions). Thus, older adults continue to represent the highest proportion of sedentary adults, despite their knowledge of the widespread health benefits associated with PA and exercise or even their intentions to engage in such behaviors. Consequently, the benefits of PA and exercise are not being fully realized and health problems perpetuate. Developing evidencebased interventions that establish sustained changes in MVPA and exercise behaviors in older adults is a major public health priority, but this requires going beyond social-cognitive constructs.The broad goal of my dissertation is to advance scientific understanding about the neural systems associated with changes in MVPA behaviors among sedentary older adults.Emerging evidence indicates that nonconscious processes also regulate exercise behaviors, stemming from accumulated affective responses from past exercise experiences (e.g., pleasant vs unpleasant). Grounded by current understanding about affect's role on decision-making, the present study hypothesized that physiological changes induced by single bouts of PA serve as somatic markers in the brain that guide future PA-related behaviors. Specifically, my dissertation extended previous research by testing whether acute exercise responses in affect-related brain systems predict PA behavior change following a 3-month exercise intervention. This hypothesis is supported by prior research indicating that self-reported changes in affect (i.e., pleasant/unpleasant feelings) during moderate-intensity exercise reliably predicts future MVPA behavior. The results of my dissertation advances previous findings by investigating how these affective responses to exercise are ii Public Abstract Despite knowing the health benefits of living a physically active life, most people remain physically inactive, especially in the older population. The goal of this project is to use functional neuroimaging to determine whether the brain's acute response to exercise influences changes in future exercise behavior. By better understanding the brain's role in making decisions to exercise, we can establish a framework for future studies to develop more effective interventions for older adults to increase physical activity in daily life. v