Cardiopulmonary exercise testing (CPET) is a non-invasive assessment of cardiovascular and pulmonary function, which can be quantified by measures such as anaerobic threshold (AT) and VO2peak. The anaerobic threshold is a measure of sustainable exercise, where the VO2peak is a measure of maximal exercise capacity. The AT has been assessed in different surgical groups and has been shown as a useful predictor of postoperative complications and survival. Early work has demonstrated that short periods of preoperative exercise intervention can improve AT and VO2peak. However, no work has to date been undertaken in patients prior to liver surgery.