Effects of Exercise on Glycaemic Control and Skeletal Muscle Function in Type 1 Diabetes

Exercise can be an effective intervention for the treatment of Type 1 diabetes (T1D). Incorporating appropriate exercise strategies as concomitant therapy can regress diabetic comorbidities and attenuate T1D-related glycaemic fluctuation as well as reverse declines in skeletal muscle health and function. Much remains to be elucidated in people living with T1D. The American College of Sports Medicine (ACSM) exercise guidelines have not addressed in depth the impact and benefits of exercise to the T1D population. This thesis aims to address the role of exercise in improving glycaemic control and ameliorate skeletal muscle regulation and metabolism. Consequently, the thesis examined strategies to support glycaemic control and ameliorate diabetes-related adverse effects on skeletal muscle in individuals living with T1D, including intensity-specific exercise effects, modality-specific exercise effects, and concurrent training interventions. Study 1 systematically assessed existing literature and demonstrated limited understanding regarding the impact of exercise in T1D. Moreover, the exercise modality, duration, and intensity on improving glycaemic control and augmenting skeletal muscle health. Study 2 demonstrated that compared to time-matched acute aerobic versus resistance training alone, acute combined (COMB) exercise is more efficacious given its potentiation of glycaemic variability and skeletal muscle inflammatory, metabolic and IGF-1 gene expression. Study 3 established that COMB training alone improves aerobic fitness, strength, skeletal muscle health and in people living with T1D, but these improvements are less substantial when compared to age and gender matched non-diabetic population. Finally, study 4 demonstrated that the neuromuscular profile did not differ between people living with T1D and Non-D groups. Previous reports of fatigue and delayed recovery from exhaustive exercise and decreased performance adaption (study 3) is not linked with motor unit degradation but in fact driven by the influence of diabetes on the molecular regulation of skeletal muscle and underlying development of diabetic myopathy. Collectively, these studies support the potential for exercise interventions to improve glycaemic control and enhance skeletal muscle health in people living with T1D. The findings from these studies conclude impairments to muscle fatigability, glycaemic control and skeletal muscle health in T1D. These results advocate the importance of exercise in this cohort, demonstrated through the disease-related impairments when compared to the non-diabetic population. These findings enhance the efficacy of COMB exercise having the most desirable effects on both acute and long-term health outcomes in people living with T1D, and provide a rationale to include COMB exercise as a concomitant therapy for T1D.