Increased daily physical activity is effective in the prevention of type 2 diabetes and several of the components in the metabolic syndrome. However, dedicated efforts in exercise training will also be effective in the treatment of the metabolic syndrome. The effect on glycaemic control is of the same order of magnitude as can be achieved by oral antidiabetic drugs. In addition, exercise (endurance and/or strength training) will also improve insulin resistance and body composition. The results are more doubtful for the dyslipidaemia and hypertension, but if the training is combined with an appropriate diet, these abnormalities are also correctable.