Physical Activity and Quality of Life in Fibrotic Lung Diseases After Initiating Anti-fibrotic Therapy and Pulmonary Rehabilitation (Actigraphy)

Inclusion Criteria: Recently diagnosed (within 24 months) patients with PF-ILD, including IPF, as defined in the 'study population' Patients of 40 years and above and MMRC functional class II or higher Patients willing to provide consent and comply with study procedures Patient agrees to complete pulmonary rehabilitation program during the study period Patient must be antifibrotic naïve or on antifibrotic therapy for less than three months. To be included into the trial, the participant must be on a stable dose of immunosuppressants (for underlying disease causing ILD) and/or antifibrotic therapy for at least 30 days prior to enrollment. Subjects must be able to walk >150 meters in their screening 6MWT FVC ≥ 40% of predicted and DLco between 30% to 80% of predicted Exclusion Criteria: PF-ILD including IPF patients who have already completed pulmonary rehabilitation within a year. Patients with acute exacerbation or active lung infection within 3 months prior to screening PF-ILD including IPF patients who are already receiving antifibrotic therapy for more than six months. Patients with significant pulmonary hypertension (PH)- defined as previous clinical or echocardiographic evidence of significant right heart failure, history of right heart catheterization showing cardiac index ≤ 2 l/min/m2 and PH requiring parenteral therapy with epoprostenol or Treprostinil. Metastatic malignancy under active treatment or active malignancy which would affect mobility Presence of concomitant severe or very severe chronic obstructive pulmonary disease (COPD) by ATS criteria.17 Mild to moderate cases will be included into the study. Presence of significant emphysema in CT scan of chest as determined by the study investigator PF-ILD patients who have limited mobility as a result of their underlying autoimmune disease Severe fatigue in sarcoidosis patients with fatigue associated sarcoidosis (FAS) score ≥ 35 Patients requiring full-dose systemic anticoagulation, or with any other contraindication to nintedanib use Patients with active and symptomatic coronary artery disease Morbid obesity, defined as BMI>35 Symptomatic moderate to severe valvular heart disease Known NYHA class-III heart disease or echocardiographic left ventricular ejection fraction ≤ 40% Inability to maintain oxygen saturation >88% with physical exertion despite supplemental oxygen Inability to ambulate for any reason Inability or unwilling to perform the required tests Presence of any other condition, that in the judgement of investigators may interfere with trial participation or may put the patient at risk when participating in the trial during the entire trial period. Women of childbearing potential will be advised to avoid becoming pregnant while receiving treatment with nintedanib and to use highly effective contraceptive methods at initiation of, during and at least 3 months after the last dose of nintedanib. Those patients who refuse to comply with abovementioned advice would be excluded from participating in the trial. Patient with moderate (Child Pugh B) or severe (Child Pugh C) hepatic impairment. Patients with signs and symptoms of acute myocardial ischemia. Patients with arterial thromboembolic events, known risk of bleeding and gastrointestinal perforation.