The purpose of this study is to determine the effects of a home-based exercise intervention on walking ability in people with peripheral artery disease. In 200 patients with peripheral artery disease (PAD), the investigators are conducting a randomized controlled trial to determine whether a patient-centered home-based exercise program improves walking ability, physical activity, mobility, pain, and social functioning, compared to a usual care group.

Lower extremity peripheral artery disease (PAD) is a common and chronic condition that affects 8 million people in the United States. PAD patients have difficulty walking because cholesterol blockages in their leg arteries prevent adequate oxygen supply to leg muscles during that activity. PAD patients reduce their physical activity levels and slow their walking speed to avoid leg pain.

Few therapies are available to help PAD patients improve their walking limitations. Treadmill exercise programs that require three or more supervised exercise sessions per week at an exercise facility can help PAD patients walk with less pain. However, most people with PAD do not participate in supervised exercise programs because they are not paid for by medical insurance and the requirements are burdensome for the patients.

The investigators have engaged PAD patients and relevant stakeholders to develop a home-based exercise intervention that is tailored to the needs of the patients. Our home-based exercise intervention includes a Fitbit activity monitor and a coach who will telephone PAD participants at regularly scheduled intervals. PAD patients will use the Fitbit to help them monitor their exercise behavior. The coach will use well-established behavioral methods during the scheduled telephone calls to help PAD patients adhere to regular walking exercise.

The investigators will conduct a randomized controlled trial of 200 patients with PAD to determine whether our home-based walking exercise program significantly improves walking performance and other patient-centered outcomes at the nine-month follow-up, compared to usual care.

PAD patients selected the trial's outcome measures as those that best represent PAD patients' physical limitations. All outcomes are well-validated and accepted outcome measures. The primary outcome measure is the six-minute walk test, an objective measure of walking endurance. Secondary outcomes consist of the Walking Impairment Questionnaire and the PROMIS questionnaires that assess patient-perceived walking ability, mobility, pain, and social functioning.

If our home-based exercise intervention is successful, the intervention will have a substantial impact on the large and growing number of people disabled by PAD.

Inclusion Criteria:

1. Participants with an ankle brachial index (ABI) ≤ 0.90 will be eligible for participation.
2. Participants with an ABI > 0.90 but ≤ 1.00 who experience a 20% drop in ankle pressure after the heel-rise exercise will be eligible.
3. Participants with an ABI > 0.90 who have medical record evidence of prior lower extremity revascularization for PAD will be eligible
4. Participants with an ABI > 0.90 who have medical record evidence of PAD based on non-invasive vascular laboratory testing or based on angiographic findings will be eligible. Non-invasive vascular laboratory evidence of PAD must be obtained from a vascular laboratory.

Exclusion Criteria:

1. Above or below knee amputation, critical limb ischemia, wheelchair confinement, foot ulcer, non-English speaking, significant visual impairment that interferes with walking activity, hearing impairment that interferes with full study participation, unable to return to the medical center or fitness center at the expected visit frequency, or unwilling to use technology required for the intervention.
2. Individuals whose walking is limited by a condition other than PAD.
3. Greater than class II NYHA heart failure or angina. Increase in angina, angina at rest, abnormal baseline stress test.
4. Major surgery including lower extremity revascularization or orthopedic surgery during the prior three months or anticipated in the next nine months.
5. Major medical illness including lung disease requiring oxygen, Parkinson's disease that impairs walking ability, or cancer requiring treatment in the prior two years (potential participants may still qualify if they were diagnosed with non-melanoma skin cancer in the past two years or if they have had treatment for an early stage cancer in the past two years and the prognosis is excellent).
6. Heart attack, stroke, or coronary artery bypass surgery in the last 3 months.
7. Mini-mental status examination score < 23, dementia, or psychiatric illness.
8. Currently walking regularly for exercise at a level comparable to the amount of exercise prescribed in the intervention
9. Currently enrolled in another clinical trial, exercise trial, or in cardiac rehabilitation. Currently enrolled in a clinical trial or current participation in cardiac rehabilitation or a trial of a therapeutic intervention within the past three months. For a clinical trial of a stem cell or gene therapy intervention, potential participants will be potentially eligible immediately after the final study visit for the clinical trial, so long as s at least six months has passed since the participant received their final treatment in the stem cell or gene therapy study .
10. Deemed a poor candidate for the study or poorly suited for the intervention (at PI discretion).