What type of nutrient is primarily broken down as an energy source during exercise?

During exercise, carbohydrates serve as the primary source of energy. The body relies on carbohydrates because they can be quickly converted into glucose, which is essential for energy production. Once consumed, carbohydrates are stored in the muscles and liver as glycogen. During physical activity, especially high-intensity exercise, the body preferentially taps into these glycogen stores.

Fats, while also a significant energy source, are metabolized more slowly and are typically utilized during lower-intensity or prolonged activities, making them less efficient for immediate energy needs during exercise. Proteins mainly play a role in muscle repair and growth rather than serving as a primary energy source. Water, while crucial for overall hydration and maintaining bodily functions during exercise, does not provide energy but rather supports processes necessary for energy metabolism. Therefore, carbohydrates are essential for supplying the quick energy required during more strenuous physical activity.