Exercise caution when stressed: Stages of change and the stress-exercise participation relationship

Objectives: To examine the relationships between stress events/intensity and exercise frequency, intensity, and duration, and to determine whether stage of change moderates these relationships. Design: Prospective, 6-week longitudinal observational study. Method: College-aged females (N = 95) were recruited from undergraduate classes and completed a battery of questionnaires before a 6-week evaluation period. During this period, participants were asked to return a daily exercise log and to return a weekly stress events scale (Weekly Stress Inventory: Brantley, Jones, Boudreaux, & Catz, 1997). Results: HLM analyses revealed that exercise stage of change interacted with stress (both event frequency and intensity) to effect: (1) the amount of exercise minutes/day reported per week, (2) the number of days of exercise/week, and, (3) mean RPE for exercise/week. For those in the maintenance stage, the number of stressful events were positively related to exercise frequency, intensity, and duration. This relationship was negative or nonexistent for all other stages combined. Likewise, stress intensity showed a positive relationship with exercise duration and a minimally positive relationship with exercise frequency for maintenance stage exercisers, compared to a negative relationship for all other stages combined. Conclusions: These results suggest differential patterns of exercise engagement based on stage of change - with those in maintenance responding to stress with enhanced activity, while those in other stages were more likely to reduce physical activity. Implications for intervention design and theories of exercise behavior change are discussed.