Investigating the Role of Perceived Willpower in Predicting Exercise Behavior-A Longitudinal Analysis on Gym Members

Abstract

PURPOSE: Implicit Theories about Willpower (ITW) propose that the beliefs of an individual's willpower as either abundant/rejuvenating or a limited resource predicts repetition of self-regulated behaviors, such as exercise. It is also theorized that willpower could be a determining factor for long-term behavioral adherence. While the ITW has demonstrated predictive validity for various health behaviors, its role in the context of exercise is limited. The purpose of the study was to test how the ITW predicts behavior among regular exercisers using an extended dual-process model.

METHODS: Participants (n= 161) were a sample of adults (18-65) recruited across nine gym and recreation centers in a large metropolitan city and were averaging 257 min/week (SD = 171) of moderate-to-vigorous physical activity. Participants completed online surveys that were assessed monthly for six months. Multi-level structural equation modeling was used to analyze the results.

RESULTS: The model found Intention X planning interaction to predict behavior (β = .29, p < .001), while controlling for intention (β = -.08, p = .14) and planning (β = -.01, p= .85). Specifically, high intenders with specific plans predicted behavior. Habit was also found to predict behavior (β= .11, p = .005). Intrinsic motivation predicted both habit (β = .25, p < .001), and the interaction construct (β= .18, p< .001) directly and behavior (β = .17, 95% CI [.070, .278]) from total direct and indirect pathways. Rejuvenating willpower predicted habit (β = .11, p = .020) and intrinsic motivation (β = .11, p = .008) directly in addition to the interaction construct (β =.10, 95% CI [.019, .184]) and behavior (β= .09, 95% CI [.001, .193]) via total pathways. The model did not find limiting willpower predict any paths. Time did not predict changes in the observed model.

CONCLUSION: Findings add support to previous work on proposed maintenance constructs by testing them longitudinally in post-intenders. The model further advances these findings by identifying how willpower, particularly, perceived rejuvenating willpower played a pivotal role as a proximal predictor of habit and intrinsic motivation and a distal predictor to behavior. Exercise-focused interventions that help participants cultivate rejuvenating willpower could be beneficial for behavioral maintenance.