Postoperative Electrical Muscle Stimulation Two

Inclusion Criteria: * Adult patients (age 18 or over at the time of diagnosis made at MDT (multi-disciplinary team meeting) * MDT outcome of colorectal or gastric cancer or non-invasive neoplasia (tissue-proven, or radiologically diagnosed and clinically suspected) with the intention to treat with curative abdominal surgery * Agreed management plan for open or minimally invasive (laparoscopic or robot assisted) segmental abdominal (colonic or gastric) resection at the Royal Derby Hospital * Sufficient mobility and fitness to complete normal ERAS (enhanced recovery after surgery) protocols following surgery * Basic conversational spoken English language * Ability to give informed consent Exclusion Criteria: * Upper GI (gastrointestinal) cancer requiring thoracotomy/thoracoscopy * Pre-existing neuromuscular disease (including Parkinsons disease) * Pacemaker, implantable cardiac defibrillator or other implanted nerve stimulator device * Metal prostheses or other metal-work in either upper legs (hip/knee/femur) * Dementia or other cognitive problem or language barrier causing an inability to follow instructions and operate NMES machine * Inability to give informed consent * Disability preventing completion of ERAS after surgery (requiring Zimmer frame/wheeled frame/wheelchair to mobilise or bed-bound) * Peripheral vascular disease * Epilepsy * Pre-existing diagnosis of chronic kidney disease or estimated glomerular filtration rate \<60 on screening visit * Pre-existing diagnosis of liver disease * Intubation or intensive care admission during study period (between day 0-5 post-op); (surgical high dependency unit patients will be included) * Return to theatre for surgical complication within first 5-days post operation * History of rhabdomyolysis * Pregnancy * Deep vein thrombosis within past 6-months * Allergy to whey protein * Patient refusal of whey protein products on grounds of dietary requirements or intolerance * Participating in another clinical trial concurrently or within the last 6 months * Known infection with blood borne virus