 Subjects Recruitment and Sampling: Fifty different subjects N50 will participate in the project, reflecting the available veteran patient population. The sample will include primarily men, of any age and ethnicity. Twenty-five subjects will have PAD and will be identified and recruited via convenience sampling primarily from the Physical Medicine and Rehabilitation PMR Outpatient Clinic, Diabetes Clinic, and Peripheral Vascular Clinic at the VA West Los Angeles Healthcare Center VAWLAHC. Other participants may be recruited from other VA Greater Los Angeles Healthcare System locations, specifically the Los Angeles Ambulatory Care Center and the Sepulveda Ambulatory Care Center. Twenty-five normal healthy control subjects will be recruited via convenience sampling from well veterans and the general community; the two groups will be matched on gender and age. We plan to enroll 25 subjects with PAD for the three-month exercise training intervention. 