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

Patients with peripheral arterial obstructive disease (PAOD) often have complaints of intermittent claudication. This causes a great limitation in the quality of life because of reduction in walking ability. PAOD is associated with increased morbidity and mortality. Beside other therapies, training has been shown to be an effective treatment option for patients with intermittent claudication. Exercise training significantly increases walking distance and consequently the functional behaviour of the patient. Several authors have identified different mechanisms involved in this beneficial effect. The most important are discussed in this review, namely adaptation or redistribution 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 in pain perception and an effect on the cardiovascular system. It is concluded that training works through a combination of mechanisms. Further research is needed to clarify the precise mechanisms.