Concept:Carbohydrate loading increases glycogen stores in muscles. This provides sustained energy for long-duration activities.Explanation:Endurance events like marathon running require continuous energy over hours. Carbohydrates are the primary fuel for such prolonged efforts. Boxers, sprinters, and powerlifters rely more on short bursts of energy or strength. Their performance does not benefit as much from extra glycogen storage. Marathon runners, however, need high carbohydrate intake beforehand to delay fatigue. Thus, carbohydrate loading is specifically recommended for distance runners.Answer:Marathon Runners (Option A)