What is the purpose of carb loading?

The purpose of carb loading is to increase glycogen stores before prolonged activity, making it the most appropriate answer. Glycogen is the body's primary energy source during high-intensity exercise, particularly in endurance events that last longer than an hour. By significantly increasing carbohydrate intake prior to such events, athletes can enhance their glycogen reserves in the muscles and liver. This boosts endurance and performance, allowing for greater sustained energy levels during the activity.

The other options, while related to aspects of athletic preparation, do not accurately reflect the primary goal of carb loading. Losing weight before an event typically involves a reduction in caloric intake and increased physical activity, which contradicts the concept of carb loading focused on increasing energy stores. Hydration is indeed critical for athletic performance, but carb loading itself does not serve the purpose of hydration. Similarly, preventing injuries is important for athletes but is not directly influenced by the carbohydrate loading process, which is specifically aimed at optimizing energy availability during prolonged exertion.