When carbohydrate fuel (glycogen) in muscles is used up, it is difficult to maintain the high initial workload unless the blood glucose concentration is elevated by carbohydrate feedings. Athletes call this condition__________________________?

The correct answer to the question: "When carbohydrate fuel (glycogen) in muscles is used up, it is difficult to maintain the high initial workload unless the blood glucose concentration is elevated by carbohydrate feedings. Athletes call this condition__________________________?" is "Hitting the wall".