Inclusion Criteria:  Aged 18-85 Sex: male/female Radiological/tissue cancer diagnosis Curative cancer of the colon, rectum, colorectal liver metastases (CRLM) of 2 or more segments elective surgery (planned a minimum of 3 weeks from the date of first clinic meeting) Access to digital technology(mobile phone, tablet or laptop, home computer) to participate in supervised home exercise  Exclusion Criteria:  Exclusion  Palliative disease Haematological malignancy Pregnancy Emergency surgery Physically unable to undergo CPET Part of any other trial with similar interventions unless previously agreed on with all CIs synchronous disease (operation on HPB & colorectal cancers at the same operation) No access to digital technology(smart phone, tablet, laptop or home computer)