The investigators propose a pilot project to assess the effect of a 16 week aerobic exercise program on arterial stiffness and cardiovascular risk in the hemodialysis population. The primary objective will be to assess the effect of a 16 week exercise program on aortic pulse wave velocity as the vascular parameter and gait speed as the physical functioning parameter. The secondary objectives will assess the effect of the exercise program on ultrafiltration rates, weight, SBP, DBP, BNP, hsTroponin, serum calcium, phosphate, albumin, glucose, LDL, HDL, TG, glycated hemoglobin, hemoglobin, CRP, micro RNAs (21, 126, 133, 146a, 221/222 and 210) and hospitalizations.