Endothelial progenitor cells (EPCs) are circulating precursor cells that have been implicated recently in vascular and cardiac regeneration. There is an ongoing discussion on the immunocytological definition of EPCs, based on various surface markers, and currently different cell types are included in the term 'EPC'. This review summarizes the mechanisms that influence function, survival, mobilization and differentiation of EPCs. Furthermore, there are several reports on the clinical use of EPCs for the treatment of cardiovascular diseases. We have focused specifically on the influence of physical activity on EPC function.