When does the fat burning start during cardio training?

Cardio training is the secret recipe for effective fat burning . If you want to lose weight quickly, you try more or less voluntarily on the cross trainer, the treadmill or during a running unit in the park at home. But are these spontaneous “short trips” into the world of endurance training really as effective as everyone thinks?

How does fat burning work during cardio training?

If we want to understand the actual functionality and effects of cardio training, we have to look for a differentiated approach. In general, cardio training is simply seen as a good way to burn fat quickly and effectively.

In the afternoon, they stand on the treadmill in the air-conditioned cellar for another 15-20 minutes so that the afternoon coffee snack doesn’t hit the conscience and the scales too hard. But is it really that simple?

Endurance training is actually a training method that aims at hypertrophy (adaptation) of the organism to increasing (training-induced) loads. In contrast to muscle building training, the difference with cardio training is that the systems involved do not primarily perform muscle hypertrophy so that muscle strength, muscle volume or muscle cross-section and intramuscular coordination are improved.

During cardio training hypertrophies primarily all systems that are needed to cope with “endurance-intensive” loads. On the one hand, there is the supply of oxygen (breathing, lung function, diffusion) and the cardiovascular system, which is responsible for the transport of oxygen and other nutrients.

On the other hand, endurance training optimizes the type of energy supply, through which the muscles regulate the respective energy supply in a stress phase.

While in muscle building mainly creatine phosphate and carbohydrates (glycogen) are used for the ATP resynthesis and thus the maintenance of the muscular performance, the situation is different with cardio training. Here, the energy supply shifts with increasing exercise duration into the aerobic area , in which finally almost exclusively fatty acids are oxidized (under the influence of oxygen “burned).

When does cardio training begin to burn fat?

The effectiveness of cardio fat burning depends primarily on three important factors:

• The training intensity
• The duration of the load
• The availability of high-energy substrates

If you look at our colorful scale, you will see that cardio training represents a (very slow) transition to interval training if you look at the type of energy supply. However, there is no exact point in time when fat burning during cardio training explicitly starts.

Burning fat is a complex process that takes place at all times. Depending on the type, duration and intensity of the load, the percentage of the total energy supply only shifts in favor or disadvantage of fat burning.

The red area represents high-intensity training and is used by maximum strength training listed in intensity. In MK training, the energy supply takes place almost exclusively via anaerobic energy supply processes, which ensure a rapid accumulation of lactate in the muscles. However, such an intense load as occurs during MK training can only be mastered by metabolizing glycogen or creatine.

The further we go into the green area , the more fatty acids are oxidized and the lower the training intensity. Our body is not able to cope with high-intensity loads through fatty acid oxidation. If there are no longer enough energy supplies in the form of glycogen or creatine phosphate for the ATP resynthesis, it simply interrupts the performance if the exercise intensity continues. Hello performance slump!

Cardio training only burns significantly more fatty acids after a duration of about 30-60 minutes . Thus, 15-20 minute jogging units are just enough to somewhat empty the athlete’s full glycogen stores.

So you would have to regularly complete endurance units of around 60-90 minutes or after your strength training in order to be able to burn fat effectively.

The “fatburn” endurance training should therefore be of low intensity and long duration. At a heart rate of 130 beats / minute, primarily fatty acids are oxidized. If the intensity increases, the oxidation of the carbohydrates increases and the fat burning is minimized. Better to run slowly forever than short and fast!

If you want to burn fat and lose weight, actual cardio exercise is only a secondary factor. Much more important than the choice of endurance exercise is the duration and intensity of the training!

Control the intensity of cardio training

So that you can really burn fat effectively and in the long term with cardio training, you should train within the so-called continuous performance limit . In this area, the lactate production in the muscle is equal to the lactate elimination through the reconstruction or breakdown of lactate.

If the lactate level in the blood and muscles rises too quickly, the glycogen stores are empty and the burning of fat increases, but with a significant drop in performance and even a drop in performance. A lactate-related acidification of the muscles leads to increasing impairment of glycolysis and is therefore counterproductive for performance. The muscle virtually traps itself. Awesome.

In order to achieve this ” lactate steady state “, one should also monitor the heart rate during cardio training in addition to the actual duration. Depending on the individual training status of an athlete, the ideal pulse rate for a steady state may differ slightly.

A stepless intensity regulation g should therefore be the basic requirement when using cardio equipment. This is the only way to easily approach your personal ideal intensity for maximum fat burning during cardio training .

When is the best time for cardio training?

As soon as muscle building training and endurance training are combined, low-intensity cardio training, about 30-60 minutes, should ideally be carried out on the days when no strength training is performed. In this way, the trained muscle groups are given maximum regeneration time that is not impaired by cardio training. In addition, blood circulation is promoted, nutrients are transported and harmful substances are removed from the muscles.

In principle, cardio training can also be connected to a power unit . The advantage of the direct combination consists in the glycogen stores that are completely emptied through strength training.

Endurance training of low intensity can not only improve the removal of lactate and thus reduce hyperacidity in the muscles, but also cause increased fatty acid oxidation. However, the cardio training should then last 30 minutes or more.

Cardio training in the morning (before breakfast) is also very effective from the point of view of fatty acid oxidation, because a large part of the previously filled glycogen stores was emptied over the night. If these are not replenished directly with a high-carbohydrate breakfast, this effect can be useful for a morning endurance session.

Our recommendation for really efficient fat burning during cardio training:

• Empty glycogen stores before cardio training (e.g. through strength training or over the night)
• Complete cardio training within the endurance limit (pulse about 130)
• Tendentially longer training duration (> 30-45 minutes) and therefore lower training intensity

Good luck with losing weight!