There is an infinite number of opinions about optimal fat burning, which often makes it difficult to keep track. Here we introduce you to the physiological basics and the principle of fat burning. Only with these are truly sustainable results in weight loss.
Why does your body burn fat?
We describe a way of providing energy in which your body resynthesizes its basic source of energy – the high-energy phosphate ATP – from fats. Unfortunately, this process is still equated with losing weight, although it basically uses different effects than improving it. Fat burning is the ability to oxidize fats and extract energy from them.
Fat burning: Particularly pronounced in endurance-trained athletes
Basically, your body is able to use carbohydrates or fats for energy. In addition, under certain conditions, the minimal protein metabolism is possible. It can be taken for granted that endurance-trained athletes have a particularly pronounced capacity for the oxidation of fatty acids. Only then are they able to use fat as an energy source even when the carbohydrate stores are no longer sufficiently filled.
The other way around can be spared for stress periods where high levels of energy are needed quickly. (1) While the oxidation of fats can rely on very large energy stores, anaerobic carbohydrate degradation is much faster and delivers as well as a higher level of energy in a given time available.
The process of fat burning
It is stored in the fatty tissue under the skin. But also in the musculature we have small fat stores. At the beginning of a workout, a reaction of the nervous system leads to a stimulation of lipolysis. This means that more and more fatty acids from the tissue are converted to glycerol, which can then be further degraded. Pouring chemical messengers such as epinephrine and norepinephrine also stimulates lipolysis.
Muscular fat is also burned
Contrary to other assumptions, physical activity activates fatty acids from the very beginning – a process that is always active to a lesser extent, even at rest. Your body uses a mix of fatty acids from the intramuscular stores and from the fat cells. Well-trained athletes have larger fat stores within their muscles and access them more strongly. The fatty acids are then transported to the mitochondria, where the oxidation ultimately takes place. Lipolysis – that is, the breakdown of fatty acids – is influenced by many factors. However, the most important control variables are hormones such as epinephrine and norepinephrine (stimulating) and insulin (inhibiting).
These factors are critical in weight loss
The intensity of exercise is a major factor in the conversion of fats under load! As mentioned above, anaerobic carbohydrate combustion can deliver more energy in a short time. So, if your body can not contribute enough energy for maintaining performance with its it’s increasingly being switched to anaerobic carbohydrate combustion. Although some studies have described the relationship between low stress intensities and fat oxidation, this has only recently been demonstrated for a wider range of intensities.
How Carbohydrate and Fat Burns Decrease and Increase
Carbohydrate combustion increases proportionally to exercise intensity, initially aerobic, then anaerobic at higher intensities. on the other hand, it increases initially, but decreases again at higher load intensities. If it is now stated flat rate that the fat burning at low load intensity to be trained, this is not true! Depending on the objective and the level of fitness, there are different stress areas in which the fat oxidation rate reaches its maximum. In addition, exercising in the area of the highest turnover of fatty acids seems sensible only with concerted goals in endurance sports or in patients.
At what intensity do you burn the most fat?
The intensity of stress that causes you to burn most fat may or may be a factor in health sports. Therefore, the question of the optimal fat burning zone is very interesting. A number of recent studies have attempted to identify those areas where the highest levels of lipid metabolism activity are to be measured. While in trainers mean intensities of 62-63% of VO2max are stated, in untrained people it was found that the maximum was about 50% of VO2max. However, the trained athletes showed a very wide fluctuation range, which was between 45% and 70% of the VO2max.
In fact, the exact identification of maximum fat burning is not so important, as the maximum can range over 5-10% of that intensity. In a comparative study with obese people, it was recently shown that fat burning and especially insulin sensitivity after 4 weeks training with 3 training sessions per week showed significant increases compared to interval training. (2) However, in terms of training, the maximum Fat burning no sensible goal.
The small difference: fat burning and gender
There are no qualitative differences in the metabolism between women and men. Nevertheless, the majority of scientific studies suggest that the female organism burns more fats than the male. In a recent study, 150 men and women were compared across different intensity ranges. It turned out that women in all areas than men, and that their maximum fat burning occurs at a higher intensity. However, these differences are rather small and physiologically probably not important.
The Significance of Load Duration and Load Type
It is no secret that fat metabolism gains in importance as load increases. During ultra-endurance competitions, such as the Race Across America or the multiple Ironman distances, fat burning can be up to 1 g / min. However, one before and during exercise inhibits fat burning.
The load duration plays a major role in the systematic planning of the training, because continuous training adjustments can only be guaranteed in the long term by increasing the load. The form of activity is also very important when it comes to fat burning. Studies have shown that fat burning is greater for a given oxygen intake while running than cycling. The reason for this is unclear – but could be found in the fact that lower muscle parts are involved in locomotion than when running.
Exercise boosts your fat burning
Alone regular physical activity provides a secure approach. In particular, endurance training leads to an increased presence of enzymes actively involved in lipid metabolism. In addition, endurance training can increase the density of mitochondria and improve blood flow through improved capillarization. Both mechanisms act on fat oxidation. Changes in the enzyme content can already be detected after 4 weeks of regular training. However, no reliable statements can be made.
There is no definite “fat burning zone”
In a study of 300 participants, the maximum fat metabolism rate was examined. The subjects showed different levels of fitness – from professional athletes to overweight and inactive people. The VO2max varied between 20.9 and 82.4 ml / kg / min. Interestingly, although maximum fat oxidation and maximal oxygen uptake were correlated, (3) however, this did not suggest fat burning at individual fitness level. Obese people showed similar metabolic rates as professional athletes. Obviously, the fat burning is also very dependent on the. The view presented in this article also shows that the “fat burning zone” does not exist. It is a construct that has been established in sports practice for years and that in reality is more complex than previously thought.