Osteoarthritis is a debilitating chronic disease which has no cure or effective treatment. If no changes are made in prevention and treatment, osteoarthritis will continue to represent a significant economic burden to patients and society. The goal of this thesis was to determine the effects of moderate aerobic exercise and prebiotic fibre supplementation on the onset and progression of the metabolic knee osteoarthritis phenotype in rats exposed to a high-fat/highsucrose diet. This study was divided into three phases. Phase 1: we evaluated the effects of a 12- week aerobic exercise program of varying duration on healthy rat knee cartilage. We determined that moderate, high and extra-high duration treadmill exercise has no detrimental effects on knee joint health, function and integrity. Therefore, we concluded that treadmill exercise at any tested duration was a safe exercise for rats in terms of knee osteoarthritis-like damage, and therefore, could be used as a safe exercise intervention in a pre-clinical rat model of knee osteoarthritis. Phase 2: we evaluated the effects of moderate aerobic exercise, prebiotic fibre supplementation, and the combination of exercise and fibre over a 12-week intervention in rats exposed to a high-fat/highsucrose diet that has been shown to cause knee joint damage. Our findings indicated that prebiotic fibre and aerobic exercise prevented knee joint damage in this model. Phase 3: we evaluated if the damaging effects of the high-fat/high-sucrose diet could be delayed/reversed. We determined that neither prebiotic fibre supplementation nor aerobic exercise were able to stop the progression of existing knee osteoarthritis-like damage induced by a high-fat/high-sucrose diet. In summary, this thesis provides insight into two different approaches to prevent the development of metabolic osteoarthritis phenotype. However, the studies presented in this thesis were not able to show an effective way to stop the progression of the disease.