THE THEORY OF PLANNED BEHAVIOR AS RELATED TO INTENTION TO EXERCISE AND EXERCISE BEHAVIOR

We sought to assess the usefulness of the theory of planned behavior in explaining the exercise behavior of 73 healthy, middle-aged adults (23 women and 50 men) enrolled in a medically-oriented, supervised, and structured exercise program. A significant moderate correlation was found between intention to exercise and both fitness attitude (r = .38, p = .001) and subjective norm (r = .35, p < .01), thus, supporting the theory of planned behavior. However, no correlation was found between intention to exercise and perceived behavioral control. The correlation between intention to exercise and exercise behavior was moderate and inverse (r = −.28, p < .02), and in conflict with a primary consideration of the theory of planned behavior. We, therefore, sought to explain this apparent illogical negative correlation by partitioning the study participants into four groups based on a median split of their intention to exercise scores and exercise frequencies: high intention/low behavior (n = 21), low intention/high behavior (n = 21), low intention/high behavior (n = 18), low intention/low behavior (n = 15), and high intention/high behavior (n = 19). Frequencies within the four intention/behavior groups (χ2 [3, n = 73] = 1.027), as well as gender (χ2 [3, n = 73] = 4.624) and age group by decade (χ2 [12, n = 73] = 13.203), were not significantly different (α = .05). Results of MANOVA procedures using the intention/behavior groups as independent variables and scale scores as dependent variables indicated significant main effects for fitness attitude (p = .002) and perceived behavioral control (p = .001), but not for subjective norm (p > .05). Post hoc Tukey tests for fitness attitude indicated significant differences only when high intention conflicted with low intention, irrespective of exercise behavior. Perceived behavioral control showed opposite tendencies (i.e., comparisons of high behavior and low behavior groups were significantly different, irrespective of high or low intention to exercise scores). We conclude that for this population, perceived behavioral control defines one's ultimate fitness behavior while fitness attitude defines one's intention to exercise. Providers in the fitness industry may implement our findings by recognizing that expectations of actual exercise behavior would be foremost predicated on an individual's perceived behavioral control.