Are antioxidants deleterious in physical exercise?

Type 2 diabetes mellitus is increasing worldwide at epidemic rates and is associated with both microvascular and macrovascular complications. Metabolism in these patients is characterized by a combination of peripheral insulin resistance primarily involving muscle fibre, combined with an inade­quate cell response despite normal or even increased amounts of circulating insulin. Physical exercise has been shown to be effective in preventing type 2 diabetes in high risk individuals and may even improve cardiovascular risk factors in patients with manifest diabetes. Likewise physical exercise improves glucose metabolism in the insulin-resistant state by facilitating the translocation of glucose transporters (GLUT-4) to the muscle membrane thereby improving insulin resistance independent of the insulin receptor pathway. This effect is even independent of exercise-related changes in body mass.