 4.2 AIMS This is a pilot study of health volunteers to assess the role of carbohydrate CHO preload and carbohydrate-protein CHO-P Highfive energy source 1 in 4 in improving aerobic capacity after a period of fasting mimicking the current starvation policy prior to surgery. Both of these have similar calorific value and only differ in the amount of carbohydrate and protein supplementation. 