 Major non-cardiac surgery has a high degree of morbidity and mortality. Recently, measurement of a patients preoperative cardiorespiratory reserve, performed non-invasively by cardiopulmonary exercise testing, has been shown to be predictive of outcome following non-cardiac surgery. All patients prior to major surgery are starved for a minimum of 6 hours and often longer prior to major elective surgery. It has been shown that elite athletes who are hypohydrated have reduced exercise capacity and lower cardiorespiratory function. These results are further exaggerated in non-trained individuals. Therefore, the starvation policy prior to surgery may have a deleterious effect on outcome after surgery. 