Which nutrient primarily contributes to energy for high-intensity exercise?

Carbohydrates are the primary source of energy for high-intensity exercise due to their ability to be rapidly broken down into glucose, which is then used by the body for quick energy. During high-intensity workouts, the body relies heavily on anaerobic respiration to meet energy demands, and carbohydrates are metabolized more efficiently than fats or proteins in this context. This is particularly important in activities such as sprinting, weightlifting, or high-intensity interval training, where the demand for immediate energy is critical.

Fats, while important for energy during lower-intensity exercise and long-duration activities, cannot be utilized as quickly as carbohydrates. Proteins primarily serve as building blocks for tissues and are not a primary energy source unless in cases where carbohydrate availability is severely limited. Vitamins, on the other hand, do not provide energy but instead support metabolic processes and overall health. Thus, carbohydrates are the preferred fuel source for supporting the energy needs of high-intensity exercise.