Idiopathic pulmonary fibrosis (IPF) is a chronic and potentially fatal lung disease. As IPF progresses, patients become increasingly breathless with reduced exercise capacity and quality of life. A cardiopulmonary exercise test (CPET) is a gold standard way of assessing patients with IPF.

An incremental shuttle walk test is simpler, cheaper, more widely available and anecdotally preferable to CPET. The investigators will compare the measurements made in an ISWT and a CPET in patients with IPF . We aim to determine whether sufficient information can be gathered in an ISWT to negate the need to undertake CPET.

Idiopathic pulmonary fibrosis (IPF) is a chronic and potentially fatal lung disease. As IPF progresses, patients become increasingly breathless with reduced exercise capacity and quality of life. Average life expectancy is three years from diagnosis but IPF progresses at different rates in different people. In 2012 the British Lung Foundation estimated that 32,500 in the UK had IPF.

An accurate prognosis can help determine the most appropriate individual treatment option and allow patients and their families to make suitable plans. Currently, measurements from resting lung function tests are used to predict prognosis. However, measurement made during CPET are more sensitive survival predictors and CPET is the gold standard test to assess prognosis in IPF. A CPET test is relatively time-consuming and requires specialist equipment that is not universally available. CPET is not routinely used in clinical practice for the assessment of IPF.

The incremental shuttle walk test (ISWT) is quicker, cheaper and more widely available than CPET. This study builds on previous research done by the Respiratory team which showed a linear relationship between the distance walked in an ISWT and peak oxygen consumption during a CPET, a useful prognostic predictor, in patients with interstitial lung disease. 40-50 patients with IPF will be recruited and will undertake both ISWT and CPET at University Hospital, Coventry. The investigators will compare the results in the current cohort to those of the previous study.

Additionally, the research team will compare oxygen pressure in capillary blood at the end of an ISWT and a CPET. The investigators will also compare patient experience of the two tests using questionnaires. This study paves the way for a simple, standardised test to more accurately predict prognosis in IPF.

Inclusion Criteria:

• Diagnosis of idiopathic pulmonary fibrosis confirmed by a multi-disciplinary team.
• Aged 16 or over
• Able to give informed consent to take part
• Able to undertake both a cycle ergometry test and an incremental shuttle walk test without needing walking aids

Exclusion Criteria:

• An inability to give informed consent.
• Taking part in a research project with a potentially research-modifying intervention
• Currently pregnant.
• Currently breastfeeding.
• Unable to perform an incremental shuttle walk test.
• Unable to perform an incremental cycle ergometry test.
• Unable to walk without an aid such as a stick or frame.

Adult patients with a confirmed diagnosis of idiopathic pulmonary fibrosis who are under the care of the Respiratory team at University Hospitals Coventry and Warwickshire NHS Trust.