Type 2 diabetes is associated with neurocognitive deficits and increased risk for dementia, with high prevalence of diabetes occurring in old age. There are many known risk factors for diabetes, including physical inactivity, obesity, and prediabetes. Studies show that individuals who are at risk for diabetes (i.e., have one or more risk factors) already experience some brain deficits seen in diabetes. One way to combat these deficits is aerobic exercise; however, the effects of resistance exercise in this population are relatively unknown. The objectives of this thesis were to report on the current evidence of brain deficits in prediabetes, and to assess the feasibility and preliminary efficacy of resistance training to improve cognition and brain health (structure and function) in older adults at risk for diabetes. A systematic review of cross-sectional and longitudinal studies assessing brain dysfunction in prediabetes was conducted, as well as a 26-week pilot feasibility randomized controlled trial of resistance exercise among older adults at risk for diabetes (i.e., those living with prediabetes and/or obesity). The systematic review found that adults with prediabetes may experience deficits in structural connectivity, but whether deficits in brain volume and cerebrovascular health are present is somewhat inconclusive and may be due to inconsistencies across study methodologies. Results from the pilot feasibility trial found that resistance exercise, compared to balance and stretching exercise, may improve selective cognitive functions, mainly task-switching, selective attention, and response inhibition. Resistance exercise also led to less age-related decline in total brain volume, less hippocampal atrophy, and increased functional activation patterns that mimic that of younger adults and healthy older adults. When assessing feasibility, study adherence, retention, and self-reported enjoyment were high, but recruitment was shown to be challenging. As such, important recruitment recommendations for improving future trials are included in this thesis. In conclusion, resistance exercise may lead to some improvements in cognition and brain health in older adults at risk for diabetes, however a full-scale, powered RCT is needed to further explore these possible effects
