Excess post-exercise oxygen consumption (EPOC) is a measurably increased rate of oxygen intake following strenuous activity. The extra oxygen is used in the processes that restore the body to a resting state and adapt it to the exercise just performed. These include:
- Hormone balancing
- Replenishment of fuel stores
- Cellular repair
- Anabolism
- Replenishment of Creatine Phosphate
- Metabolism of lactate
- Temperature recovery
- Heart rate recovery
EPOC is accompanied by an increase in consumption of fuel, which leads to an increase in consumption of energy. The net effect is that the harder you work, the more fat you will burn after you finish the exercise session!
Duration of the effect
The EPOC effect is greatest soon after the exercise is completed and decreases to a lesser level over time. EPOC can increase metabolic rate and therefore the rate of fat burning for a period of up to 48 hours after the conclusion of the exercise, depending upon the intensity and duration of the activity.
Size of the EPOC effect
The EPOC effect exists after both anaerobic exercise and aerobic exercise, but anaerobic exercise increases EPOC more than that of aerobic exercise. For exercise regimens of comparable duration and intensity, aerobic exercise burns more calories during the exercise itself. However, the difference is partly offset by the higher increase in caloric expenditure that occurs during the EPOC phase after anaerobic exercise. Anaerobic exercise in the form of high-intensity interval training will also result in greater loss of body fat, even though fewer calories are used during exercise.
What is clear is that the EPOC effect is greater, the greater the intensity of the exercise, and the greater the time spent during the exercise phase.
An important factor in increasing EPOC, together with the amount of energy expended during your exercise session, is to create variety. By placing differing stresses on the body, in the form of a variety of exercises and the intensity of those exercises, you will cause a greater adaptation and therefore a greater level of energy consumption (fat burning).