All participants will have a physical activity monitor placed onto the right thigh in the midline which will start collecting data at midnight on the first postoperative day. This will continue until discharge or day 7, whichever is earlier. This is a non-invasive measure of activity and can discriminate between whether a patient is lying, sitting, standing or walking. There is no control group.

Recruited patients from the colorectal clinic at the Royal Derby Hospital will be invited to be included in the study, and can either attend the University of Nottingham, Centre Of Metabolism, Ageing & Physiology (COMAP) research group unit at the Royal Derby Hospital Centre or discuss the trial in detail over the phone after which a consent form will be sent to them (either by post or email). If they agree to inclusion in the study the consent form will be brought with them to be completed on the day of surgery. On the morning of surgery they will have their consent recorded and the activPAL™ accelerometer applied to the anterior thigh.

The activPAL™ is a non-invasive physical monitor that records periods spent, lying, walking and engaging in more strenuous activity. This will remain in situ for 7 days, or until discharge, whichever comes first. The investigators will ask participants to complete a short diary to note down any times the monitor is removed and the time of sleep and waking. After removal - the data is uploaded (it does not include any person-identifiable data) for analysis using software on a local computer in the COMAP unit. After discharge, they will have 2 x telephone calls and/or emails at day 10 and at day 28 to follow up from the research team to monitor progress for the next 30 days. If they develop any complications including readmission data within that time period, this will be collected from the participants' notes along with demographic data and postoperative pathology and recorded. Complications will be graded as per the Clavien-Dindo Classification system.

On postoperative day 3, day 5 and day 7 (if still an inpatient) they will also be asked to complete the Hospital Anxiety and Depression Scale (HADS) paper questionnaire. Just prior to discharge, they will complete the discharge questionnaire.

Inclusion Criteria:

• Aged 18 years and over
• Clinical diagnosis of colorectal cancer due to undergo surgical resection with curative intent
• Must be able to give informed consent

Exclusion Criteria:

• Lacking capacity to consent
• Undergoing emergency surgery
• Undergoing defunctioning surgery prior to neoadjuvant treatment
• Undergoing surgery with palliative intent

All patients presenting to Royal Derby Hospital who have gone through colorectal multidisciplinary team (MDT) meeting with a plan for surgical resection of colorectal cancer with curative intent.