As patients with adrenal insufficiency also exhibit an adrenomedullary dysfunction and patients who suffer from both, adrenal insufficiency and type I diabetes more frequently report hypoglycemia, particularly after strenuous activities this study investigates the counter-regulatory hormonal response to physical stress and the impact on cognitive function in subjects with and without Addison's disease, type I diabetes and healthy subjects. Patients will perform ergometer training with an individualized intensity and fulfill cognitive function testing (stroop test and fatigue inventories) before and after strenuous activity.