Pilot Study of Nitrate-rich Beetroot Juice Supplementation in Patients With Idiopathic Pulmonary Fibrosis (IPF)

IPF Patients: Inclusion Criteria 1. Patients aged 18-85 years with a prior specialist multidisciplinary team diagnosis of idiopathic pulmonary fibrosis (IPF) based on current established consensus guidelines. 2. Medical Research Council (MRC) breathlessness grade 1-3 3. Judged clinically stable for 3 months prior to recruitment by the investigator. IPF Patients: Exclusion Criteria 1. Baseline spirometry with FEV1/FVC ratio \< 0.7. 2. Neoplastic disease undergoing treatment or active follow up. 3. Presence of infection or exacerbation requiring hospitalization, within last 3 months. 4. Current tobacco smoker or use of nicotine containing vapes (within 3 months) 5. Current use of ambulatory or long-term oxygen therapy (LTOT). 6. Peripheral oxygen saturations \<85% during 6-minute walk-test. 7. Any condition which would prevent completion of cycle-ergometer testing, pulmonary function testing (PFT) or 6-minute walk testing as judged by the investigator. 8. Participation in a pulmonary rehabilitation (PR) program in the last 3 months. 9. Any condition excluding CPET based on the absolute contraindication as the ACCP/ATS guidelines 2003 10. Positive pregnancy test in females of childbearing age. 11. Symptomatic peripheral vascular disease 12. Concomitant use of nitrate-based medicine or phosphodiesterase V inhibitors Controls: Inclusion Criteria 1\) Age and sex-matched to participants in the IPF cohort. Note: the participants will be age-matched within a 5-year age bracket. Controls: Exclusion Criteria 1. Inability to give informed written consent. 2. Malignancy (except localised squamous or basal cell skin carcinoma) undergoing active investigation, treatment, or follow-up. 3. Significant cardiorespiratory disease as judged by the investigator. 4. Diabetes mellitus requiring treatment with pharmacology therapy. 5. Current tobacco smoker or use of nicotine containing vapes (within three months). 6. Symptomatic peripheral vascular disease. 7. Concomitant use of nitrate-based medicine or phosphodiesterase V inhibitors.