Afterburn Effect , afterburn phase, afterburn effect – it has many names. But what is it about the myth of the “afterburn effect”? We clarify! But first we make a little digression into the energy supply of our body so that we can understand the energetic processes that take place during and after training a little more precisely.
Energy supply and afterburn effect
Regardless of whether we struggle out of bed overtired, grumpily push our lawnmower over the long overdue, almost meadow-like lawn or push the chrome-plated barbell out of its holder in the gym – every muscle contraction requires energy to to convert electrical impulses triggered by our nervous system into mechanical muscle movement (contraction).
This energy is provided by the main energy carrier of our body – the ATP. Because we have already discussed this topic intensively in several articles and in our training program, we will only briefly address the essential basics at this point.
The ATP reserves stored in the muscles are usually only sufficient for about 1-2 seconds to supply the muscle contraction with energy. If the ATP supply is exhausted, the ATP supply can be resynthesized in a certain way over a period of about 5-20 seconds (depending on the amount of stored creatine phosphate) via the metabolism of creatine. But this process also reaches its limits at some point. Even with minimal long-lasting stress phases through pure strength training (e.g. bench press, deadlift or squat) or a combination of strength and cardio training, such as Sprint training, the endurance performance is clearly required and the organism puts its energy supply on the anaerobic glycolysis or the oxidative combustion of carbohydrates and fats . If all available carbohydrate stocks are oxidized, your metabolism has to rely almost entirely on fatty acid oxidation. Your depot fat begins to melt and your lifebuoys are getting smaller and smaller. However, fatty acid oxidation only becomes significantly more important after around 30-60 minutes of exposure.
What is the afterburn effect actually?
The so-called “Afterburn Effect” actually describes a metabolism-specific property that occurs especially after long and intensive training sessions. We already know that the majority of our energy supply is achieved almost entirely through the metabolism of ATP and creatine phosphate during short periods of stress. But what happens if we turn off the creatine phosphate tap ourselves?
From an exercise duration of around 8 minutes upwards, the oxidation (combustion) of glucose (carbohydrates) and fatty acids plays the decisive role in the Energy supply on With increasing exposure time with a constant medium intensity, as is eg is the case during fat burn training with the ergometer or jogging, the oxygen requirement also increases continuously for the purpose of increasing oxidation of carbohydrates and fatty acids. This rapid increase can lead to a deficit in the oxygen balance in the first few minutes of a prolonged stress phase of the metabolism, because the oxygen-regulating processes (an increased heart rate and stroke volume ensure increased transport of the oxygen diffused in the lungs from breathing via the blood) can only adapt to the actual oxygen demand due to increasing stress with a delay. This creates a temporary oxygen deficit, which is compensated in the ” afterburning phase”.
If the long-lasting muscular stress phase is now interrupted or ended (end of training), the increased breathing and heart rate continues for some time so that the oxygen deficit can be removed again. The now “excess” oxygen is not simply wasted, but is used effectively for the resynthesis of creatine phosphate (here we had to “turn off the tap” beforehand) or to burn the accumulated waste product lactate. That is the actual Aferburn Effect that we are talking about.
Incidentally, after training, the lactate is burned by the heart and muscle fibers rich in mitochondria and built up again into glucose via the liver so that it can be made available again for energy supply. An efficient process.