Why is training effective in the treatment of patients with intermittent claudication?

Patients with peripheral arterial obstructive disease (PAOD) often have com plaints of intermittent claudication. This causes a great limitation in the quality of life because of reduction in walking ability. PAOD is associate d with increased morbidity and mortality. Beside other therapies, training has been shown to be an effective treatment option for patients with interm ittent claudication. Exercise training significantly increases walking dist ance and consequently the functional behaviour of the patient. Several auth ors have identified different mechanisms involved in this beneficial effect . The most important are discussed in this review, namely adaptation or red istribution of the peripheral blood flow, inhibition of the progression of the atherosclerotic disease, changes in blood rheology, metabolic changes, changes in skeletal muscle morphology, economisation of walking, a change i n pain perception and an effect on the cardiovascular system. It is conclud ed that training works through a combination of mechanisms. Further researc h is needed to clarify the precise mechanisms.