Which nutrient is primarily used for energy during high-intensity exercise?

During high-intensity exercise, carbohydrates serve as the primary source of energy. This is due to their capacity to be rapidly broken down into glucose, which can then be utilized by the muscles for quick energy production through glycolysis. Unlike fat, which is primarily used for energy during lower intensity or longer-duration activities, carbohydrates can provide a fast and efficient source of energy that matches the quick demands of high-intensity efforts.

Protein, while it can be utilized for energy, is generally reserved for situations of prolonged exercise or when carbohydrate stores are depleted, and it is not the primary source during high-intensity workouts. Vitamins do not provide energy directly; rather, they serve as coenzymes and are involved in various biochemical reactions in the body. Therefore, the reliance on carbohydrates during high-intensity exercise is well-established in nutritional science, emphasizing their crucial role in maximizing performance and endurance in such conditions.