Obesity and type-2 diabetes can be considered diseases of physical inactivity. Physically activity protects against type-2 diabetes through its positive effects on weight management and on the metabolic pathways involved in glycemic control that are not weight-dependent. Increasing physical activity is one of the most effective strategies both for preventing type-2 diabetes and for managing it once it is present. However, we still face an enormous challenge in getting people to achieve sustainable increases in physical activity. A promising strategy is to get people walking more, starting small and increasing gradually over time.