Last year the chemical examination1of the blood of a group of runners who participated in the American marathon race held in Boston, April 19, showed that the sugar content of the blood at the finish of the race was moderately diminished in two runners and markedly diminished in four. There was, furthermore, a close correlation between the physical condition of the runner at the finish of the race and the level of the blood sugar. It was found that those competitors who had extremely low blood sugars presented a picture of shock not unlike that produced by an overdose of insulin. In making the report, it was suggested that the adequate ingestion of carbohydrate before and during any prolonged and vigorous muscular effort might be of considerable benefit in preventing the hypoglycemia and the accompanying development of symptoms of exhaustion.2 In preparation for the next annual race,