Methods Patients with colorectal liver metastases suitable for hepatic resection will undergo a baseline CPET and then be randomised to either preoperative exercise intervention or standard care. Patients within the intervention arm will undergo a 4 week exercise program consisting of 3 interval sessions per week on a stationary bike. This will be individually tailored according to their initial exercise test. In the week prior to surgery all patients will then undergo a further CPET. At surgery liver tissue will be taken to determine hepatic gluconeogenic capacity. CPET tests will then be performed where possible in patients at 6 weeks and 3 months following surgery. Post-operative complications (Clavien classification and Postoperative morbidity score (POMS)) and 30 and 90-day mortality will be recorded. Quality of life assessments (EORTC/SF-36) will be taken at recruitment, the week prior to surgery, 6 weeks after surgery and 3 months following surgery.