Type 2 diabetes (T2D) is a significant health issue in New Zealand, with a high prevalence reported in adults aged 65 years and over (older adults) and in Maori and Pacific people. Cardiovascular disease is the leading cause of death in adults with T2D. Ageing and T2D are both associated with a reduction in exercise capacity. The filling capacity of the heart becomes less effective as people age, and this decline appears to be accelerated in people with T2D. The filling capacity of the heart is important during exercise, and therefore this may explain why exercise capacity is lower in people with T2D. Therefore, the purpose of this research is to examine the effect of T2D on cardiac function at rest and during exercise in adults ranging from 35-80 years. This research will also examine whether three months of exercise training can improve cardiac function in older adults with T2D.