Cardiovascular disease, in particular coronary artery disease (CAD), is the leading cause of death in industrialised countries. Current therapeutic approaches to obstructive CAD include pharmacologic reduction in myocardial oxygen demand or mechanical restoration of blood flow to regions with insufficient blood supply. Alternatively, recent investigations have focused on the growth of vascular communications between different coronary artery regions. In principle, vessel growth occurs by the formation of a primary plexus of vessels by angioblasts (vasculogenesis), by sprouting of endothelial cells leading to a new capillary network (angiogenesis), or by the transformation of pre-existing collateral arteriolar pathways into conducting vessels (arteriogenesis).¹ In occlusive CAD, angiogenesis takes place in the presence of myocardial ischaemia while the remodelling process of arteriogenesis is related to enhanced shear forces at the vessel wall in response to increased flow through pre-existing collateral connections.² Theoretically, this renders physical exercise an ideal therapeutic option for inducing arteriogenesis, since cardiac output, and thus coronary flow, is elevated along the arterial branches of the coronary circulation.³ In humans without stenotic coronary arteries, it has recently been shown that there can be functional anastomoses between different vascular territories.⁴ However, proof of the …