What process primarily contributes to caloric expenditure after exercising at high intensity?

The process that primarily contributes to caloric expenditure after exercising at high intensity is Excess Post-Exercise Oxygen Consumption, commonly referred to as EPOC. After engaging in high-intensity exercise, the body's demand for oxygen remains elevated as it transitions back to its resting state. This increased need for oxygen results in heightened metabolic activity, which facilitates the consumption of additional calories during the recovery phase.

EPOC encompasses various physiological processes including the replenishment of oxygen stores, clearing lactic acid, restoring ATP and creatine phosphate levels, and normalizing body temperature. As a consequence, the body continues to burn more calories even after the workout has concluded, which is a distinctive feature of high-intensity exercise. This effect can last several hours, depending on the intensity and duration of the workout, making it a significant contributor to overall caloric expenditure post-exercise.