What is the after burn effect and when does it occur?

The afterburn effect, also known as excess post-exercise oxygen consumption (EPOC), refers basically to the increased quantity of calories burned after exercise. Physical activity increases muscles' demand for oxygen (VO2), which oxidizes carbohydrates and fats, producing the energy required for movement. The demand of the human body for oxygen increases proportionately with the intensity of your workout. During intense exercise, your body needs more oxygen than breathing could provide. This gap between the demand for oxygen in the muscles, and the actual amount of oxygen delivered is called the "oxygen debt". In order to "pay off" the oxygen debt, restore balance and "cool off", the human body usually needs a few hours. In that time, it consumes more than 10 liters of extra oxygen, thus burning more calories post–workout.

To take advantage of this fascinating ability of the body and enjoy the reward of extra calories burned, you should make sure you train the right way.

Studies have shown that one of the main factors influencing the accelerated burning of calories after the workout is the intensity of the activity. With an increase in the exercise intensity, the magnitude and duration of EPOC increases. Low-intensity physical effort has shown the smallest effect on post-exercise calorie burning. The effect of combustion after the completion of intensive training can take up to 10 hours.

Another factor influencing the post-exercise calorie burn is training duration. The principle is simple: shorter duration of EPOC is observed after exercises with lower intensity and shorter duration, and the greatest impact of EPOC follows a long high-intensity workout. This theory applies not only to aerobic exercise, but also to resistance training.

And what effect does fitness level have on post-exercise calorie burn?

Fit people regenerate quickly after exercises, and their "oxygen debt", heart rate and blood pressure return to normal in a relatively short time.

After training, fit people burn more calories than an untrained person, because they may train with greater intensity, for a longer time. Thus, a more athletic person might have a higher EPOC, but the duration of the post-workout energy consumption will be longer in the case of an untrained person – they need more time to restore the body to the state of rest.

Note, however, that the afterburn effect is not the Holy Grail when losing excess weight. Training of appropriate intensity and duration is essential because most calories will burn during the actual training, and the ensuing EPOC effects are just an additional perk. Given the fact that the post-exercise combustion may take up to 48 hours, we can lose weight even while sleeping. That's worth a lot of commitment during every workout. It really pays off! If you have further questions, please contact our professionals.

Lidia Zamyłko
Regional Business Studio Manager, Fitness Instructor
Holmes Place Poland