Physical activity in the management of type 2 diabetes mellitus

 The incidence of type 2 diabetes mellitus (T2DM) is rising throughout the world. Explicit evidence has demonstrated sedentary behaviour is a powerful but modifiable risk factor affecting glycaemic control and the incidence of diabetes complications. Despite this, current population estimates indicate the importance of physical activity is not effectively translated to the T2DM population. The aim of this thesis was therefore to investigate barriers and facilitators to physical activity behaviour among individuals with T2DM. An extensive literature review investigating evidence linking physical activity to the management of T2DM was performed, then followed on by three studies which 1) investigated the effects of a 12-week supported exercise programme among newly diagnosed patients, 2) explored factors that may be associated with sedentary or physical activity behaviour, and 3) compared and contrasted the perception and use of physical activity among patients who participated in an exercise programme and patients who received standard care. The findings of this thesis demonstrated that a supported exercise programme can help newly diagnosed T2DM patients achieve moderate-high intensity physical activity 3-5 days·week-1, improving glycaemic control through enhanced β-cell function associated with decreased insulin resistance and improved lipid profile. Exploratory investigation suggested self-efficacy to exercise, internal locus of control and physical activity advice may be important antecedents for physical activity behaviour. Furthermore, it also appeared to suggest that peer support and more comprehensive physical activity information and reinforcement, are key to satisfying psychological needs - autonomy, competence and relatedness - and internalising motivation for physical activity and exercise behaviour. Given the projected incidence of T2DM and prevalence of sedentary behaviour among this population, the findings from this thesis highlight the important role of physical activity and also the need for further research investigating supported exercise programmes and the development of more comprehensive physical activity guidelines for individuals with T2DM.