Advances in our understanding of the value of carbohydrate-electrolyte solutions have come from information derived from two major fields of study--exercise physiology and sports nutrition--and from research on diarrheal diseases. Research in the first area has been concerned with physical performance, primarily of athletes. Research results have demonstrated that even small fluid deficits have adverse effects on performance through elevated heart rates, reduced sweat rates, and elevated body temperature. Glucose-electrolyte solutions have been found useful in rehydration and in preventing dehydration. Carbohydrate is needed to facilitate sodium and water absorption. Other ions may or may not be needed, depending on sweat losses or losses from the gastrointestinal tract. Advances in exercise physiology also have demonstrated the value of carbohydrate solutions in providing energy for muscular activity in endurance events that last at least 60 minutes and involve vigorous exercise.
Diarrhea is a major, perhaps the most important, contributor to death of infants and preschool children in less-developed countries. Death rates are being reduced around the world through the use of oral rehydration therapy (ORT), which involves the use of carbohydrate-electrolyte solutions and is based on the same basic physiologic mechanism as the rehydration solutions given to athletes, i.e., the provision of glucose to promote the absorption of sodium and potassium ions and of water.
Both these established uses for carbohydrate-electrolyte beverages have potential military applications. Military personnel are often called upon to perform heavy physical activity during training or combat conditions in very