Promoting exercise behaviour: an integration of persuasion theories and the theory of planned behaviour.
The purpose of this study was to examine the effectiveness of a theoretical integrated persuasive message on exercise motivation in college students. Four hundred and fifty introductory psychology students (M age = 20.02 years; SD = 3.94) were randomly assigned to reading positively or negatively framed strong messages advocating exercise. The messages were attributed to a credible source, a non-credible source or to a no-source control condition. Theory of planned behaviour (TPB) constructs (i.e. attitude, subjective norm, perceived behavioural control) and cognitive responses (i.e. thought listing) were measured immediately and 2 weeks following the delivery of the intervention. Unfortunately, the results did not corroborate previous research, as we did not find any significant effects between experimental groups on any psychological or behavioural variable. There may be several potential explanations for the lack of effects, including the interaction between the type of persuasive information (TPB implications) and sources of persuasion and how these persuasive messages are processed (elaboration likelihood model/cognitive response implications). The theoretical implications of this research are discussed with a view towards future directions for exercise promotion initiatives using theoretically driven interventions.