 The investigators wish to explore the hypothesis that decrease in exercise capacity fitness associated with NAC prior to upper gastrointestinal cancer resection may outweigh the benefits duration of survival achieved by NAC in some patients undergoing upper gastrointestinal cancer surgery. The investigators aim to recruit 175 patients from over 36 months. Consenting patients will perform cardiopulmonary exercise testing CPET and complete a quality of life questionnaire prior to and 4 weeks after NAC . Postoperative outcomes measured at set time points will be objective recorded including mortality 1 year after surgery and short term postoperative harm described by the PostOperative Morbidity Survey POMS as well as Quality of life scores and resource use e.g. hospital bed utilisation. Exercise capacity fitness before and after NAC will be assessed using CPET and the relationship between the derived variables AT, VO2 peak and clinical outcomes will be described. 