Fat and carbohydrate metabolism during exercise in late-onset Pompe disease

► Metabolism was examined with stable isotopes and indirect calorimetry. ► Peak oxidative capacity was severely reduced to less than half normal in patients. ► Fat and carbohydrate oxidation during sub-maximal exercise was normal in patients. ► Glucose supplementation did not improve exercise capacity in patients. ► This indicates that exercise intolerance in Pompe disease is structurally related.