Subjects randomized to exercise training will participate in a three-month treadmill exercise program in 1-hour training sessions three times per week as previously described. After a 5-minute warm-up period, exercise is initiated at a low workload of 2 mph at 0% grade. Subjects walk until moderate claudication severity develops, and then rest until the discomfort resolves, repeating until the total exercise period is completed. The intensity of the treadmill exercise is increased as tolerated by increasing walking speed by 0.5-1 mph and/or grade by 1-2%. Subjects are encouraged to continue the walking program at home for at least 30 minutes on two separate occasions each week.

Subjects randomized to the routine activity control group will be asked to keep a log of their daily activities and return to the Vascular Research Center at weeks 4, 8, and 12 at which time they will be asked to return their log and undergo repeat treadmill testing and complete the 6 minute walk test.

Subjects randomized to exercise training will participate in a three-month treadmill exercise program in 1-hour training sessions three times per week as previously described. After a 5-minute warm-up period, exercise is initiated at a low workload of 2 mph at 0% grade. Subjects walk until moderate claudication severity develops, and then rest until the discomfort resolves, repeating until the total exercise period is completed. The intensity of the treadmill exercise is increased as tolerated by increasing walking speed by 0.5-1 mph and/or grade by 1-2%. Subjects are encouraged to continue the walking program at home for at least 30 minutes on two separate occasions each week.