Lifestyle is universally considered a fundamental issue in the prevention and therapy of both type 2 diabetes and metabolic syndrome. However, implementation at a general population level of recommendations resulting from available evidence is largely insufficient. In particular, only a limited fraction of the general population meets the recommended levels of aerobic physical activity, and individuals meeting the recommended levels of resistance physical activity are even less. Interestingly, there is further reduction in these proportions in subjects with prediabetes and especially in those with type 2 diabetes. It is noteworthy that people with or at risk for diabetes represent a significant proportion of the general population, show objective evidence of impaired exercise capacity, for different mechanisms, and frequently have long-standing sedentary habits, difficult to be changed. All these aspects should be taken into account, when designing in-tervention programs aimed at improving the current situation. As regards the possibility of a stable increase in physical exercise levels and reduction in sedentary habits of individuals with diabetes, available data are limited. However, they indicate that it is possible to improve these aspects in a significant proportion of subjects. Behavioral changes reported in studies are generally smaller than the prefixed improvements, but sufficient to obtain favorable and clinically significant effects. Interventions applied in these programs show several shortcomings, indicating the need for a continuous revision of strategies.