Carnitine under scrutiny: does it really work? Is it an effective fat burner?

Carnitine first became popular in the 1980s when it came on the scene as a revolutionary fat burner. However, its popularity faded over time as better, more appealing stimulant-based fat burners like the ones we know today hit the market. In addition, most of the published research on the subject of carnitine has confirmed virtually no or very little fat-burning ability. Thus, the original effect of carnitine was disproved and it was no longer considered by people as a good fat burner, even though the fat burning effect it actually has.

Today, carnitine is back and stronger than ever. What we now know is that carnitine not only helps fat burning, but also enhances performance, recovery during training, improveimproves a person's cardiovascular health, and has many other health benefits, which we'll discuss carefully here. If this supplement is not already in your supplementation plan, consider including it. I myself didn't know how much carnitine can be helpful, but I can't praise its effects enough. In this article, you'll learn why.

What is carnitine anyway?

Carnitine is often classified as an amino acid, but that's not an entirely accurate classification. Carnitine is considered to be a vitamin-like compound and an amino acid related to the B vitamins. Specifically, it is an ammonia-containing compound that is formed in the liver and kidneys from two essential amino acids, L-methionine and lysine. This process involves several vitamin C-dependent enzymes, so vitamin C deficiencies can interfere with carnitine biosynthesis. Although carnitine is produced in the liver and kidneys, it is mainly stored in the muscles, heart, brain and even sperm.

Carnitine exists in two forms, namely D-carnitine and L-carnitine. The L-form is the form found in nature and is biologically active. The D-form, on the other hand, is biologically inactive and can actually have negative effects on the body.

The most common forms of carnitine

• L-Carnitine - the same, natural form found in our bodies.
• Acetyl-L-Carnitine (ALCAR) - this form of L-Carnitine has undergone a process called "acetylation" which allows it to pass through the brain barrier. This form provides all the health benefits associated with brain function. It is designed for people who want all the health benefits of the benefits of carnitine and also want to get the most out of their fat-burning workouts. It does not need to be taken with food and is taken with stimulants (caffeine, green coffee, etc.) for maximum effectiveness.
• L-carnitine L-tartrate (LCLT) - the tartrate form of carnitine aids absorption. If effective use is desired, it is recommended to combine this form with carbohydrates and protein. It could be said that the tartrate form is the most suitable for use just after a workout or when eating a large meal containing mainly carbohydrates.
• Glycine Propionyl L-Carnitine (GPLC) - In this form, L-Carnitine binds to the amino acid glycine, creating an antioxidant effect and speeding up blood flow during exercise.

1. Carnitine really helps fat burning

The most critical and debated role that carnitine plays in the body is to assist in the transport of fats, especially long chain fatty acids, across the mitochondria of cells. Mitochondria are essentially the cell's powerhouse, where most of the ATP (adenosine triphosphate) is derived for energy. Once fatty acids cross into the mitochondria, they can be oxidized (burned) to produce ATP (energy). Without enough carnitine in the body, most dietary fats cannot get to the mitochondria and be burned for fuel.

Interestingly, one of the reasons why medium chain triglycerides (MCTs) and coconut oil (which contains MCTs) are not as easily stored in the body as fat is that they do not need to be transported into the mitochondria. Instead, they have direct access and are more easily burned for fuel. But back to long chain fatty acids.

Several research studies supports the notion that carnitine supplementation promotes fat burning, not only during exercise, but also at rest. Carnitine's ability to increase the amount of fat burned at rest means that this supplement has a great potential to aid fat loss and prevent fat gain during volume periods. Due to its ability to increase fat burning during exercise, carnitine supplementation savesIt also saves muscle glycogen and delays muscle fatigue, allowing you to train harder and longer.

Enough theory, here's some research for a practical demonstration

Researchers at the University of Nottingham have found that athletes taking carnitine during low-intensity cycling burned 55% less muscle glycogen while increasing fat burning by up to 55%. In turn, they had lower levels of lactic acid and higher levels of creatine phosphate during high-intensity cycling.

Subsequently, when they measured the athletes' ability to withstand fatigue during this test, they found thatthat those taking carnitine were able to ride more than 25% longer than those supplementing with carbohydrates alone. This is likely due to the fact that they burned more fat while maintaining a greater amount of muscle glycogen, as well as lower levels of lactic acid and higher levels of creatine phosphate.

The researchers also found that despite adding 160 grams of fast-digesting carbohydrates (640 calories) to their daily diet, the subjects taking carnitine gained no additional body fat. The group taking 160 grams of fast carbohydrates without carnitine gained more than 2kg of body fat over 24 weeks. This may be due to carnitine's ability to keep blood glucose levels low even after a large carbohydrate meal.

This is achieved by increasing glucose absorption in muscle cells, which has been shown in more than one study. Carnitine appears to increase the action of insulin in the muscle cell to aid glucose absorption. This makes carnitine a great post-workout supplement with fast carbohydrates to aid glycogen recovery. Carnitine's ability to help transfer more fat into the mitochondria of muscle cells, where it is burned for good, also is likely to help keep body fat at bay, even when consuming large amounts of fast carbohydrates daily (i.e. 160 grams).

Why do a lot of people claim that carnitine has no effect on fat burning?

Studies that have shown no benefit of carnitine have failed to adequately increasemuscle carnitine levels, but this was due to it not being delivered at the right time. Proper timing is therefore everything.

2. Improves physical performance

The benefits for physical performance stem not only from its ability to increase fat burning and reduce glycogen consumption, but also from other factors. One of these is related to increased blood flow to the muscles.

Research shows that carnitine can increase blood flow, which improves the delivery of nutrients, hormones, and oxygen to muscle fibers. This not only increases energy during training, but also muscle recovery after training. This property of increased blood flow appears to be due to its ability to increase nitric oxide (NO) levels and decreasem oxidative damage, as well as its ability to increase the activity of a key enzyme involved in NO production.

3. Helps with muscle mass and strength gains

In addition to boosting athletic performance, carnitine also has anabolic properties, which can help increase muscle growth and increase strength. Research shows that carnitine affects testosterone. Scientists at the University of Connecticut have found that carnitine increases the amount of testosterone receptors (known as androgen receptors) inside muscle cells. The more of these receptors you have in your muscle cells, the more testosterone can bind to them and stimulate muscle growth.

In addition, research shows that carnitine supplementation facilitates the action of insulin by increasing levels of one of its binding proteins, which enhances its anabolic action.

4. It improves brain function and counteracts the aging process

In addition to physical benefits, carnitine, especially acetyl-L-carnitine, also provides mental benefits. Acetyl-L-carnitine can be found throughout the central nervous system, where it plays a role in energy production and the production of the important neurotransmitter acetylcholine. The acetyl group attached to the carnitine molecule enhances its ability to cross the blood-brain barrier and enter the brain. Research suggests that acetyl-L-carnitine may provide regenerative and protective effects against the processes ofm aging and neurodegeneration, in addition to helping to maintain brain function and improve memory.

Acetyl-L-carnitine has mechanisms beneficial to the heart muscle itself during aging and looks promising as a so-called However, the practical experience today is not yet sufficiently explored.

5. It can stabilize sexual function

Furthermore, it has been foundthat carnitine can help with sexual problems. As you already know, carnitine increases NO levels (as mentioned above) and can improve blood flow. In fact , one study by Italian researchers reported that carnitine was more effective than testosterone treatment in treating male erectile dysfunction. There is also research that suggests that carnitine supplementation increases male fertility, particularly by increasing sperm mobility.

6. Positively affects blood sugar levels

Carnitine, which as you know is important for burning fat and transporting fatty acids to the mitochondria, has a positive effect on blood sugar regulation and can help lower them. If you want to know the finer details of how L-carnitine supplementation helps regulate blood sugar levels, you can go through them in more detail in the study conducted here.

7. Lowers bad LDL cholesterol

A 2009study published in the "American Journal of Clinical Nutrition" examined the effects of acetyl supplementation on oxidized low-density lipoprotein, or LDL cholesterol, in diabetics. The study used 81 people who had type 2 diabetes and lasted about three months.

The people were divided into two groups, and the results showed that those taking acetyl-L-carnitine had reduced levels of oxidized LDL. They also had reduced triglyceride levels. As a result, acetyl-l-carnitine may help manage cholesterol levels, but more research is needed.

8. Protects against heart disease

The heart stores much of the carnitine in the body. This makes sense, of course, because the heart relies on fatty acids to fuel the pumping of blood. Some studies show that supplements containing acetyl-L-carnitine can improve muscle weakness and help those who have a diagnosis of heart disease.

The most promising research supports acetyl-l-carnitine supplements for angina patients because it shows that it helps patients exercise without chest pain. Small studies suggest that those who take acetyl-l-carnitine supplements soon after a heart attack may have lessless likely to suffer another heart attack or develop further heart failure.

All these positive studies show improvements in patients with heart disease, the researchers further conclude thatthat young, healthy people who have no heart disease may not experience any of these benefits. Clearly, more extensive research is needed on this topic.

How should you take carnitine?

It is essential that you supplement carnitine at times when you are consuming fast-digesting carbohydrates (unless you are taking the acetyl form) to increaseIncrease insulin levels, for example after training, this is in my experience the best time to take carnitine. The second best time is in the morning, after a night of fasting, when you should eat properly.

The standard dose of L-carnitine is around 500mg to 2000mg. Dosage is a completely individual matter, but I recommend sticking around that higher limit to get all the possible benefits that carnitine has to offer.

Is it worth investing in carnitine?

As such, carnitine is a very functional and practical supplement that experienced athletes should include in their supplementation plan. For me personally, it is one of the essential dietary supplements and can help me in gaining muscle mass. But I admit that being a student with a limited financial budget, I prefer to invest in protein and other more important supplements.

Personally, I take carnitine in tartrate form and I take it mostlym after training and in the morning on an empty stomach for muscle recovery, performance and health benefits. For increased fat burning or brain function support I recommend taking the Acetyl form, other forms in my opinion are not necessary to buy.

Which carnitine supplement is best?

Personally, I have had a great experience with L-carnitine tartrate from Finnish brand Nutriworks. The price of one dose here is around 7-, which I think is acceptable. In fact, it is the best quality and at the same time the cheapest carnitine I have found on the Czech market.

The taste is completely neutral, so you can mix carnitine into any food or drink. The advantage of this product is that it is maximally pure without any ballastand preservatives, which is exactly what I demand from quality supplements.

If you would like L-carnitine tartrate in capsule form, I recommend the old and proven brand Prom-IN. Here the price is a bit higher, but it's not a major difference. The functionality, purity of the supplement is exactly the same, so it is up to your preference which supplement you choose.

And if you were thinking about carnitine that does not need to be combined with carbohydrates, then we recommend L-Carnitine in Acetyl form from the brand Namaximum. Again, this is a 100% pure powder with no added ethers or preservatives. There is the option to purchase the powder or tablet version.

Conclusion

If you are a regular or recreational exerciser, there are definitely better supplementsthat you can invest in. If you are not involved in sports at a competitive or professional level, taking carnitine will not be as essential for you and you probably won't feel the change as much. In that case, you're better off investing in more important supplements like a protein, multivitamin or omega 3.

But if you're a professional athlete, consider including carnitine in your regular supplementation. At the very least, this supplement is worth a try. Do you have any questions about carnitine? Feel free to ask us in the comments below, we'll be happy to answer them for you.

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• Citrulline under the microscope.
• Joint Nutrition Under the Spotlight.
• Glutamine under the microscope: proper dosage, effects and our experience
• BCAAs under the microscope: Benefits, proper dosage and side effects
• Whey Protein Under the Spotlight: Manufacturing processes, protein breakdown and benefits
• Creatine under the microscope: Synthesis, benefits, dosage and side effects
• Pre-workouts under the microscope: Uses, active ingredients and negative effects
• Omega 3 under the microscope: Proper dosage and health benefits
• Magnesium under the microscope: Benefits, dosage and its best forms
• Vitamin D3: Benefits, proper dosage and best form
• EAAs under the microscope: proper dosage, effects and supplement reviews