2 - (IOP 37) Characterization of Motivation and Exercise Avoidance in Generalized Anxiety Disorder vs. Social Anxiety Disorder

Background: Anxiety disorders are associated with elevated exercise avoidance and low exercise engagement, despite benefits of exercise for anxiety. Motivation has been shown to influence engagement in evidence-based treatment, such as exposure, for generalized anxiety disorder (GAD) and social anxiety disorder (SAD). Low intrinsic (motivated through internal factors) and high extrinsic motivations (motivated through external factors) have been implicated in increased exercise avoidance. Yet, it is unclear if there are differential patterns of avoidance or types of motivation for exercise amongst specific anxiety diagnostic types. This analysis characterized motivation and objective exercise avoidance in low-active individuals with GAD or SAD. It also explored the association between extrinsic/intrinsic motivation and anxiety diagnosis (GAD vs. SAD) with exercise avoidance.

Methods: Baseline data was examined from an ongoing exercise trial of low-active adults (N = 51; Mage = 32.6; 78.4% female; 56.9% white) with high anxiety sensitivity and a primary anxiety disorder (n = 28 GAD; n = 23 SAD) based on a structured clinical diagnostic interview. Assessments included Motivation for Exercise/Working Out Questionnaire (subscales intrinsic motivation [high scores indicate enjoyment of exercise itself; range 1-7] and external regulation [high scores indicate influence from external factors to exercise; range 1-7]), and the Willingness to Pay (WTP) task (a neuroeconomic behavioral auction task using a decision making approach to quantify objective exercise avoidance). Participants endorse what they would pay ($0-10) to avoid exercise at varying levels of intensity and time. The average WTP to avoid moderate and high intensity exercise at 10, 15, and 20 minutes was used for exercise avoidance outcome.

Results: Diagnostic differences assessed by t-tests were consistent with small to medium effects for lower intrinsic (d = 0.36, GAD:M±SD=3.95±1.59, SAD: 3.33±1.82) and external motivation (d = 0.43, GAD: 4.46±1.24, SAD: 3.83±1.69), and higher exercise avoidance (d = 0.39, GAD: $4.79±2.91, SAD: $5.90±2.77) for SAD than GAD but did not reach statistical significance (ps .063 to .161). Intrinsic motivation (B = -0.68, p = .003) was negatively associated with exercise avoidance when accounting for age (B = 0.09, p = .008) and diagnosis (B = 1.05, p = .155) in a hierarchical regression. External motivation was not significantly associated with exercise avoidance (B = 0.35, p = .203).

Discussion: Differences in motivation and avoidance suggest those with SAD (vs. GAD) may have less overall motivation for and more avoidance of exercise. Further, intrinsic motivation may be directly associated with exercise avoidance in anxiety disorders generally. Conclusions are limited by sample size; analyses will be replicated with the larger anticipated sample (~70). Findings suggest that low intrinsic motivation in those with SAD is an important treatment target for improving engagement in exercise, an effective and accessible treatment for anxiety disorders. Future work could target low intrinsic motivation using an affect-based intervention, focusing on immediate mood benefits of exercise to enhance momentary mood and motivation.