Abstract
Whilst exercise has many health benefits, for a minority, a problematic relationship with exercise can occur, typically characterised as a behavioural addiction. This thesis used mixed methods to explore problematic exercise using four empirical studies expanding beyond the medical model to incorporate the subjective experience. It also sought to understand the mechanisms that may lead to the development of problematic exercise, focusing on the role of biases and the influence of quantification on the exercise experience. Study one was a qualitative study (n = 19), utilising semi-structured interviews with frequent exercisers to understand their positive and negative experiences of exercise. Thematic analysis highlighted a spectrum of problematic behaviours and the concept of rationalising choices through a cost benefit analysis. Study two was a quantitative cross-sectional study (n = 139) utilising an online survey to understand different manifestations of problematic exercise and their relationship with learning, cognitive and emotional biases. The findings highlighted three related but distinct manifestations of problematic exercise, the medical model, the subjective experience and an objective measure of continuing to exercise despite negative consequences. These concepts were differentially related to the biases, in particular sensitivity to reward and punishment. Study three was an experimental study (n = 58) on the role of exercise quantification (present versus absent) on exercise experience and the development of problematic exercise. The findings demonstrated that quantification can impact exercise experience, such as fatigue. Problematic exercise was also associated with differing approaches to exercise induced pain. Study four aimed to qualitatively assess the impact of quantification on the experience of exercise (n = 40). Findings indicated a key role for trust, whether in the subjective experience or in the ‘objective’ data. In summary, problematic exercise is much more than that described by the medical model often involving a rational weighing up of costs and benefits. It may be facilitated through biases, specifically those relating to reward and punishment. Further, the ability to ignore fatigue may be exacerbated through quantification which may be considered a more trusted form of data than the individual’s subjective experience. These findings have implications for research, fitness and clinical settings.