Sport Fasting
Sport fasting is a short-term diet aimed at switching from carbohydrate/sugar burning to fat burning. This ‘metabolic switch’ is achieved by reducing the body’s carbohydrate intake and increasing fat burning through exercise. To protect muscle mass from breakdown as much as possible, supplements are used. If you are someone who is enthusiastic about fitness, our average reader, you may wonder why this is called ‘sport fasting’ at this point. I will also immediately give my personal opinion: As soon as a ‘new’ type of diet combines some old principles into a commercial package, a skeptical approach is advisable. Also read the article: the keto dietSport Fasting or Just ‘Cutting’
You are partly right if you say that this is simply a low-carb diet coupled with training, which is commonly referred to as ‘cutting’. People working on muscle growth need sufficient energy and nutrients. Muscle growth usually involves an increase in body fat. This period of growth, the ‘bulking’ phase, is often followed by a period focused on fat burning. Initially, enough protein is therefore provided, whether or not in the form of a supplement. Protein shakes are also offered in sport fasting. Low carbs with training and supplements, therefore. And yet sport fasting is different from a normal ‘cut’. Firstly, because the period is considerably shorter, often no longer than 10 days, although longer sport fasting periods exist. Moreover, the training is fully focused on fat burning and consists solely of cardio. Finally, not only are carbohydrates reduced, but on some days, you also consume hardly any protein. This can be supplemented with protein in the form of supplements. This is common in many diets. The difference here is that you pay much more for these supplements than usual. No strength training and expensive proteins in a calorie-restricted diet are not exactly ideal for muscle maintenance. As a bodybuilder, or anyone else interested in muscle mass, sport fasting is therefore not recommended. [Insert link to hypertrophy and muscle growth article here]Sport Fasting, All for Rapid Fat Loss?
The entire theory behind sport fasting, like the caveman diet, goes back to the time when humans were still hunters. In the past, people went hunting when they were hungry, so it was normal to be active in a period of hunger and then, after a successful hunt, to move on to a period of abundant food. When the caveman was hungry and decided to go hunting, he was effectively fasting and the body’s reserves were tapped into. The caveman no longer used sugars from the muscles for energy but the fat reserves. The aim of sport fasting is to achieve this switch to using reserves for energy generation for hunting. That this switch can also be made in practice is known. What sport fasting adds to this principle is a urine test to determine if and when this switch is made.Sport Fasting and Athletic Performance
However, it is important to realize that fats are the body’s secondary fuel. Athletic performance will therefore always decline during sport fasting. Hence the advice not to train too intensively. In theory, two advantages could arise from sport fasting. Due to improved fat burning, you may perform better during endurance sports when your body has sugar available again and is better able to burn fats. However, the question is how long the improved fat burning will last when you start eating ‘normal’ amounts of carbohydrates again. Or in other words, when you start eating the amount of carbohydrates suitable for optimal athletic performance again. The question is also to what extent the decrease in sugar burning occurs as long as the increase in fat burning is maintained. Another advantage could come from glycogen loading. Carbohydrates are stored in the form of glycogen in the muscles and, to a lesser extent, in the liver. When fewer carbohydrates come in than the glycogen consumed, muscle cells will be depleted of glycogen. When carbohydrates are then eaten again, the muscle cells can absorb more glycogen than before. So, you temporarily have a larger amount of glycogen. A principle that bodybuilders use in the days leading up to a competition. However, this effect is only temporary. You can also question to what extent such a theoretical improvement outweighs muscle loss and the lack of training during fasting.Sport Fasting and Fluid
Depleting glycogen is necessary for the metabolic switch. Only when glycogen is depleted does the body have the need to switch to burning fats. However, this also affects the amount of fluid you retain. Glycogen holds a lot of water. One gram of glycogen can hold up to 2.5 grams of fluid. The average body contains about 500 grams of glycogen in the muscles. Losing half a kilo of glycogen means losing about 1.25 liters of fluid. Together with the glycogen, you are therefore already losing almost 2 kilograms of body weight. A large part of the weight loss is therefore not due to lost fat mass. This also means that you can expect this weight to return quickly when you start eating more carbohydrates again and fill the muscles with glycogen.Sport Fasting and Contradictory Information
It is difficult to make an exact judgment about sport fasting because it is offered in different ways that are not always transparent. So, what your sport fasting looks like can vary depending on the provider, and I’m not talking about personal advice. Contradictory information is also provided about the theory behind sport fasting and the supplements that must be used. There is much emphasis on micronutrients such as vitamins and minerals in the supplements offered. So, you might think I’ll just buy a jar of multivitamins and minerals. However, on the sportvastenkuur.nl website, you can read that you should not do this at all. For example, vitamin C and E are said to block one of the triggers for the metabolic switch. This could nullify the entire effect. However, this does not stop the owners of sportvasten.nl from emphasizing the importance of antioxidants they sell for €35, which oddly enough contain vitamin C and E. At some providers, you are asked to sign up without information on the site about how sport fasting works. For me, an indication that they prefer to target customers who do not like to delve into the subject. However, you will find commercial success stories on the site that would not be out of place in a Tel Sell commercial.Sport Fasting and Euro Fasting
As soon as I read that packages of supplements are offered for €275 for a 10-day course, I really want to swipe left. But for this article, I have to look further. If I do, I see supplements being offered at a ridiculously high price. Although it cannot be ruled out that the theory of sport fasting can have beneficial effects that last longer than just a few days, the commercial aspect makes you feel perfectly justified in feeling cheated. But that’s the price you pay for not being critical. A bit of a smart shopper recognizes the ingredients of some supplements, for example, as the well-known BCAAs. After all, these have been sold for years to prevent muscle breakdown during weight loss, but for much less money. What is also striking is that sportvastenshop.nl offers proteins in the form of (whey) hydrolysate. This is protein that has already been partially broken down into smaller chains of two and three amino acids and individual amino acids. The extent to which this has happened is very important for the improved effect. We do not find this information. However, it is stated that the protein is manufactured in Ireland. Just like the whey hydrolysate from bodyenfitshop that I wrote a review about, Optipep from the Irish Carbery. It turned out to be 4% hydrolyzed, much less than other hydrolysates that Bodyenfitshop also offers with a degree of hydrolysis of over 27%. The Irish hydrolysate costs 30% less at B&F. The reason I find it strange that this more expensive protein has been chosen is that it should mainly distinguish itself in absorption rate. However, in an article about slow vs. fast proteins, I showed research indicating that limiting muscle breakdown is mainly a property of slow proteins. Fast proteins should mainly stimulate the production of new muscle mass and do this for much shorter periods. It therefore does not seem logical to use the fastest proteins while muscle maintenance is the goal and there is not enough food for muscle growth.Sport Fasting Results
There are quite a few skeptics who consider sport fasting to be just a hype. However, the people behind the company that introduced sport fasting claim that good results can be achieved in the 10-day program. For men, the result after 10 days is about 5kg of weight loss and for women, it is lower, around 3kg. In terms of scientific substantiation, not much is known yet about how this method of weight loss can work for a larger group of people. There is a study in Germany where 14 healthy men, who were in good condition because they already did recreational running, followed the 10-day program. And another group was done by a similar group for a period of 7 days. The group that followed the sport fasting program for 10 days really made the switch. From sugar burning to fat burning, and the group that followed the program for 7 days did not make it far enough to make the switch. The results of this study were as follows:- Average weight loss: 4kg
- Waist size decreased by 4cm
- Decrease in body fat percentage of 4 percent
Conclusion
Too little is known about how sport fasting can work for a larger group of people. The studies that have been done were conducted on people who were already in good condition and already had a higher resting metabolism. Furthermore, it is not new that you can lose weight through a calorie deficit and exercise. This effect can be further increased by using food supplements during this period. This makes sport fasting actually unnecessary, and you could argue that you could achieve the same with less food and more exercise. Have you experienced sport fasting? Let us know via the commentsSources
- sportvastenkuur.nl
- sportvasten.nl
