Inclusion Criteria:

• - Age 40-80 yrs at randomization.

• - Diagnosis of idiopathic pulmonary fibrosis (IPF), consistent with the ATS 2018 Guidelines.

• - Percent Forced Vital Capacity (%FVC) ≥50% and ≤90% - Percent Carbon Monoxide Diffusing Capacity (%DLCO) ≥30% and ≤90% - Willing and able to participate in an exercise regimen.

• - Ambulatory without the use of an assistive device.

• - Stable on antifibrotic therapy (pirfenidone or nintedanib) at least 3 months.

• - No changes in other medication for at least 4 wks before enrollment.

• - Must be able to read, write, and verbally communicate in English.

Exclusion Criteria:

• - Forced expiratory volume in one second (FEV1)/FVC ratio <0.7 after administration of bronchodilator at screening.

• - Expected to receive a lung transplant within 1 year from randomization or, for patients at sites in the United States, on a lung transplant waiting list at randomization.

• - Known explanation for interstitial lung disease.

• - History of asthma or chronic obstructive pulmonary disease.

• - Active infection.

• - Ongoing IPF treatments including investigational therapy, immunosuppresents (other than prednisone 20 mg daily and below) and cytokine modulating agents.

• - Participation in a supervised exercise program including pulmonary rehab within the previous 12 months.

• - History of unstable or deteriorating cardiac or pulmonary disease (other than IPF) within the previous 6 months.

• - Major orthopedic, psychiatric, neurological, or other conditions that would impair performance of the study exercise outcomes.

• - Require >5LPM supplemental O2 at rest.

- Currently pregnant

Contemporary walk test endpoints in IPF trials may under-represent patient functional gains with antifibrotic therapy, which may be more effectively captured with long-term activity monitoring. Traditional pulmonary rehabilitation centers create a barrier to patient exercise accessibility and compliance, which is eliminated in a mobile health (mHealth) exercise training approach. In this study, 30 patients with IPF will be randomized into one of two arms. The exercise arm will receive a 12-week home exercise intervention using an mHealth platform plus pre- and post-intervention monitoring (4 weeks each). The non-exercise arm will be monitored for the same study duration. The primary end point is change from baseline in daily physical activity as a number of weekly exercise minutes qualifying as moderate to vigorous physical activity (MVPA), METS*minutes of exercise per week, and sedentary time minutes. Assessments will be performed primarily via in-person study visits at week 4 and week 16, as well as via daily recordings from mHealth monitoring devices.

Arms

Experimental: Exercise Arm

antifibrotic therapy + mHealth monitoring + 12-wk mHealth home exercise prescription

No Intervention: Non-Exercise Arm

antifibrotic therapy + mHealth monitoring

Interventions

Behavioral: - 12-week mHealth home exercise prescription

3x/week home walking protocol, 2x/week resistance exercise program