An Ecological Momentary Assessment Study Investigating Self-efficacy and Outcome Expectancy as Mediators of Affective and Physiological Responses and Exercise Among Endometrial Cancer Survivors.

ABSTRACT

BACKGROUND: Previous studies have shown affective and physiological states in response to exercise as predictors of daily exercise, yet little is known about the mechanism underlying such effects. PURPOSE: To examine the mediating effects of self-efficacy and outcome expectancy on the relationships between affective and physiological responses to exercise and subsequent exercise levels in endometrial cancer survivors. METHODS: Ecological momentary assessment (EMA) surveys were delivered up to eight 5- to 7-day periods over 6 months. Participants (n = 100) rated their affective and physiological states before and after each exercise session (predictors) and recorded their self-efficacy and outcome expectancy each morning (mediators). Exercise (outcome) was based on self-reported EMA surveys and accelerometer measures. A 1-1-1 multilevel mediation model was used to disaggregate the within-subject (WS) and between-subject (BS) effects. RESULTS: At the WS level, a more positive affective state after exercise was associated with higher self-efficacy and positive outcome expectation the next day, which in turn was associated with higher subsequent exercise levels (ps < .05). At the BS level, participants who typically had more positive affective and experienced less intense physiological sensation after exercise had higher average self-efficacy, which was associated with higher average exercise levels (ps < .05). CONCLUSIONS: In endometrial cancer survivors, affective experience after exercise, daily self-efficacy and positive outcome expectation help explain the day-to-day differences in exercise levels within-person. Findings from this study highlight potentials for behavioral interventions that target affective experience after exercise and daily behavioral cognitions to promote physical activity in cancer survivors' everyday lives.