Predicting physical activity in older adults: An integrated model considering health related dispositions and the theory of planned behavior

The present study aimed to evaluate an integrated model where the variables considered in the Theory of Planned Behavior (TPB) were integrated with variables derived from the Health-Related Dispositions approach to predict the intention of sedentary elders to attend sessions of physical activity. The study was conducted on a random sample of sedentary elderly Italians aged 65-90 years. Each participant completed a questionnaire assessing Attitudes toward attending physical activity sessions on a regular base, Subjective Norms, Perceived Behavioural Control and Behavioural Intention, measured according to Ajzen and Fishbein (1980) recommendations. Health-Related Dispositions were measured by means of a specifically developed 24-item instrument: The Health Commitment & Affect Scale. Different Structural Equation Models were fitted to the data. Results suggest that the effects of Health-Related Dispositions on the intention to attend physical activity sessions are mostly mediated by TPB variables. The mediation effects cannot be explained in terms of overlapping between empirical indicators of similar constructs and provide a conceptual link connecting individual Health-Related Dispositions to the intention to regularly do physical activity.