Peripheral arterial disease (PAD) is a significant vascular condition affecting millions of adults. Exercise such as walking is highly effective for reducing PAD symptoms such as claudication (pain with walking) and improving physical function. The trial examines the efficacy of a internet-delivered walking program for patients with PAD. Comparator groups including telephone counselling, the combination of internet-delivered walking program + telephone counseling, or usual care. The primary outcome of interest is maximal walking distance.

With the aging of the American population, the numbers of adults with peripheral arterial disease (PAD) will increase significantly over the next several decades. Patients with PAD are at increased risk for morbidity and mortality including both cardiovascular and all-cause mortality. While regular physical activity reduces risk for vascular events and is recommended for treatment of PAD patients, few patients meet recommended goals. Exercise programs which increase long-term adherence to walking can be an important contribution to PAD treatment. Our Internet-based intervention, builds on a walking enhancement program developed by members of our team and is shown to improve adherence among patients with vascular disease such as coronary artery disease (CAD). Using a randomized, controlled trial study design, we propose to test an automated Internet-based walking program to improve long-term adherence to walking while increasing walking distance, and health-related quality of life, among patients with PAD. Participants will be randomized to 1 of four study groups: 1) weekly telephone counseling, 2) an Internet-based walking program, 3) a combination of telephone counseling and Internet-based walking program, or 4) a usual care group. The Internet-based walking program has been shown to increase both adherence to walking and overall walking duration in populations with chronic complex conditions such as CAD and diabetes. There is a strong need to develop interventions, easily generalizable to a real-world population, to improve the reach of lifestyle interventions which result in improved physical function and adherence to regular exercise among complex medical patients. Patients such as those with PAD (a CAD risk equivalent) stand to benefit the most from such programs.

Inclusion Criteria:

Age ≥ 40

Diagnosis of PAD due to atherosclerosis, documented by 1 or more of the following:

• documented ankle brachial index (ABI) ≤ 0.9 in at least one leg
• toe brachial index ≤ .70 for participants with an ABI > 1.3
• documented arterial disease by MRI, CT or angiogram Ability to walk at least 150 feet without the assistance of a cane or walker. Are sedentary (defined as < 150 minutes per week of physical activity). Able to obtain medical clearance from a primary care provider, cardiologist, vascular specialist, endocrinologist, nurse practitioner, or physician assistant.

Competent to give informed consent. Have regular access to a computer with an Internet connection that allows software downloading.

Be a regular email user (check email at least once a week).

Exclusion Criteria:

PAD due to non-atherosclerotic causes such as trauma, entrapment syndromes or congenital anomalies.

No primary provider, or cardiologist or vascular provider Life expectancy of under 1-year Co-morbidities which limit physical activity to a severe degree (defined as the inability to walk a grocery store aisle unassisted) Signs of critical limb ischemia and/or planned peripheral revascularization in the next 12-months

A diagnoses of any of the following cardiovascular events in the past 3 months:

• stroke/transient ischemic attack
• myocardial infarction
• unstable angina
• percutaneous coronary intervention
• coronary bypass graft surgery A diagnoses of any of the following cardiovascular conditions
• severe valve disease untreated
• complex arrhythmia untreated
• New York Heart Association class III-IV heart failure Current substance abuse, or significant psychiatric disorder, or dementia which limits the participant's ability to follow the study protocol Pregnancy Non-English speaking