It's amazing what a little exercise can do. If you're a type 2 diabetic, the effects of a single session of aerobic exercise on insulin action vary with duration, intensity, and subsequent diet; a single session increases insulin action and glucose tolerance for more than 24 hours.
An individual’s training status will affect the use of carbohydrate during an aerobic activity. Aerobic training increases fat utilization during a similar duration bout of low- or moderate-intensity activity done after training, which spares muscle glycogen and blood glucose and results in a lesser acute decrease in blood glucose.
(Colberg, Albright, Blissmer, Braun, Chasan-Taber, Fernhall, Regensteiner & Rubin, 2010)