Inclusion Criteria:  18 years of age or above. Confirmed moderate to severe inflammatory bowel disease based on endoscopic evaluation, clinical scoring tools and faecal calprotectin. Be able to provide written informed consent. Stable dose of steroids. Physically able to complete an exercise programme. Healthy controls.  Exclusion Criteria:  Inability to participate in the exercise program (unable to perform 6MWT, unable to attend for assessment of parameters at any time point). An uncontrolled cardiovascular condition such as unstable angina, uncontrolled cardiac arrhythmias, uncontrolled symptomatic heart failure or symptomatic severe aortic stenosis. A significant musculoskeletal condition, neurological condition, mental illness or intellectual disability that restricts participation in a physical exercise program. Pregnancy. Healthy controls with underlying inflammatory conditions.