The study of attitudes has interested sport and exercise scientists for a long time, although the initial research efforts were primarily descriptive (Kenyon 1968) and failed to specify clear behavioural targets for the attitudes. For example, it is unlikely that agreement with a general statement concerning one’s ‘liking’ for physical activity will predict specific physical activity behaviours such as swimming or walking. Disaffection with such limitations led to the development of the theory of reasoned action by American social psychologists Icek Ajzen (latterly changing the spelling of his name to Aizen) and Martin Fishbein (Ajzen and Fishbein 1980; Fishbein and Ajzen 1975). Ajzen’s modification of this model – the Theory of Planned behaviour has been tested extensively in the physical activity and health literature and will be discussed later.