Nutrition and Physical Performance in Military Environments

Abstract : This report is a review of research findings concerning nutritional aspects of physical performance with direct relevance to the operational requirements of military personnel. Among the macronutrients providing fuel to working muscle, only carbohydrates are relatively limited in availability. Since muscle depends on carbohydrates as an energy store for high intensity exercise performance, depletion of these stores have detrimental effects on exercise performance. In contrast, there is no consistent evidence that physical exercise performance would be enhanced by the addition of micronutrients to standard rations. Calorie restriction may be a necessity when a lightweight foodpack would be beneficial in order to save weight and volume requirements for highly mobile units. If dehydration, ketosis and hypoglycemia can be avoided, weight loss of up to about 10% will not cause drastic performance impairments. The environmental stress of heat or altitude causes an anorexia which can result in insufficient energy and/or carbohydrate intake to maintain optimal physical performance. Cold environments are usually associated with an increased energy consumption, probably because of the increased caloric cost of working in protective clothing and with specialized equipment. The implications of most environmental stresses are that the relative physiological demands of a given task are increased.