The current PAD guidelines recommend exercise training three I12] times weekly 13,17], but a twice weekly training regimen was used in prior studies 136,37] We deliberately set up a twice-weekly pro- gram because of better feasibility in clinical routine and to improve [13] patient's acceptance and compliance. In addition, aiming to opti- throughout the whole physiotherapists mize supervision by trained SET period we limited training groups to a maximum size of six patients per group. Therefore, the modest sample size ofthe present Nevertheless, we were study has to be acknowledged as limitation. able to demonstrate a clear benefit of PAD patients receiving SET in a routine setting with respect to circulating EPC and ADMA levels. We did not determine late outgrown EPC, which were shown appearance morphological to have distinct growth characteristics, compared to early-EPC endothelial-specific properties and more (CAC, EC-CFU), which were measured in our study. This method- ological difference should be kept in mind for the interpretation of the results