Colon cancer information as a source of exercise motivation

Abstract
Using a Protective Motivation Theory (PMT) framework, this study examined whether colon cancer is a meaningful source of exercise motivation. Participants were (N = 173) teaching and school staff randomly assigned into one of three treatment conditions: PMT present, PMT absent (attention control) and no information (non-contact control). Two separate DVD videos were developed (one incorporating the four major components of PMT; perceived vulnerability (PV), perceived severity (PS), response efficacy (RE) and self-efficacy (SE) featured colon cancer and exercise information while the other DVDs featured cancer and nutritional information). Following treatment, participants completed questionnaires which assessed their beliefs towards colon cancer and exercise as well as their intentions to do more exercise. Two weeks later (T1), self-reported measures of exercise behaviour were assessed and then repeated at 1 month (T2). Only physically inactive participants were used in subsequent analyses (n = 72). Results indicated that compared to the two control groups, the PMT present group scored significantly higher on RE and intention to engage in more exercise (p-values = 0.001). A trend effect in the expected direction also was noted for T1 exercise behaviour (p = 0.09). RE, SE and PV made significant and unique contributions to exercise intention scores, explaining 44% of the response variance. Intention was the only variable to show an association with T1 exercise behaviour, explaining 10% of the response variance. Overall, these findings suggest that a single exposure of media intervention grounded in theory can influence people's beliefs, motivation and initial behaviour.