Exercising in a structured versus an unstructured setting : an application of the theory of planned behaviour

Abstract

The main purpose of this study was to examine the constructs of the theory of planned behaviour (TPB) in two different exercise settings – structured versus unstructured. Owing to the assumption that individuals may perceive less volitional control in a structured setting versus an unstructured setting, it was hypothesized that perceived behavioural control would be a stronger predictor of exercise behaviour in the structured setting. A secondary purpose of the current study was to assess the utility of using two different exercise outcomes – energy expenditure and exercise frequency – to assess exercise behaviour. Participants (N = 207) were recruited from a first-year kinesiology university class. Data collection occurred over two time periods, nine days apart, and was conducted during class periods. During the first testing session, participants were provided with a questionnaire that assessed TPB constructs and physical activity level in the two settings (structured versus unstructured) using the Modifiable Activity Questionnaire (MAQ). Half of the participants were requested to complete the TPB constructs using energy expenditure as the outcome measure and half were requested to complete the constructs using exercise frequency as the outcome measure. In the second testing session, all participations were asked to report their exercise levels over the previous seven days using the MAQ. In terms of predicting intention, hierarchical regression analyses revealed that, contrary to the hypothesis, perceived behavioural control was more predictive in the unstructured setting versus the structured setting. Although not predicted, it also was found that subjective norms were a significant predictor of activity intention in the structured but not the unstructured setting. The results using the two different outcome measures (e.g., energy expenditure versus frequency) also revealed differences; however, no consistent pattern emerged. One relationship that did emerge was the finding that perceived behavioural control was found to be a stronger predictor of intention in the unstructured setting using energy expenditure as an outcome versus exercise frequency. Finally, the results revealed little support for the TPB constructs predicting self-reported physical activity behaviour. Practical implications and future directions are discussed.