1. Patients attending the Preoperative Evaluation Clinic, SGH at least 11 days prior to his/her elective major abdominal surgery. Major abdominal surgery is defined as an intraperitoneal surgery with expected length of stay beyond 2 days. For patients who attended the clinic more than 11 days prior to surgery date, they will be informed to start their prehabilitation bundle 10 days prior to surgery.