Colorectal cancer is 37% higher in the North West than the national average and is treated by chemotherapy, including fluorouracil, capecitabine, and oxaliplatin. A side effect of these drugs is loss of memory, forgetfulness, and general brain fog, which can persist for months after the end of treatment. These symptoms are collectively known as 'chemo-brain'. An existing prehabilitation intervention that has been previously developed will be used, which increases fitness and reduces hospital length of stay in colorectal cancer surgery patients, to try to improve the symptoms of chemo-brain in those undergoing chemotherapy and improve quality of life.