4 benefits of L-carnitine for bodybuilders

L-carnitine is an amino acid produced by the body that is also found in foods and supplements. In this article, we'll explore the benefits of L-carnitine for bodybuilders, including how to take it, dosage, weight loss, side effects, and more.

L-carnitine is an amino acid used by the human body to facilitate the transport of fats into mitochondria, the cells' power plants. Once in the mitochondria, these fatty acids are converted into usable energy.

Your body can produce L-carnitine on its own using two other amino acids, lysine and methionine. Over 95% of your L-carnitine stores are contained in your muscles; the rest is found in tiny amounts in your blood, liver, heart, and kidneys.

The ability to aid in fat metabolism makes extra supplementation with L-carnitine popular among individuals who do bodybuilding and seek to improve body composition.

L-carnitine's role as a fat-burning supplement is well-known. During mass-gaining phases, it can help limit fat accumulation and make mass gains "cleaner."

If you're cutting, it can help transport the fat you have into your cellular furnaces (the mitochondria) to be burned for energy.

When Nottingham researchers measured the study participants' ability to resist fatigue during a cycling test, they found that the individuals taking L-carnitine were able to cycle 25 percent longer.

This likely occurred because they converted more fat into energy while preserving muscle glycogen, as well as having lower lactic acid levels (less fatigue) and higher creatine phosphate levels.

In several human studies, doses of L-carnitine as little as 1-2 grams per day have been shown to significantly reduce muscle damage caused by intense exercise and improve recovery after exercise.

L-carnitine also appears to reduce muscle soreness. The best part? These studies weren't conducted on animals. They were conducted on healthy men and women who already had training experience. This means it wasn't a hypothesis that could be transferred to humans. It means L-carnitine actually works in humans.

The performance-enhancing benefits of this supplement come not only from its ability to increase fat burning and decrease glycogen depletion, but also from the way it can improve blood flow to the muscles. Increased blood flow means more nutrients and hormones go where they're needed most during exercise.

How does it work? On the one hand, carnitine reduces oxidative damage to the body's nitric oxide (NO). But it also increases the activity of a key enzyme involved in your body's NO production.

The net result is higher blood NO levels, which not only increase muscle swelling and energy during exercise, but also muscle recovery after exercise.

Getting straight to the point: 2 to 3g of L-carnitine with your pre-workout meal or shake. This meal or shake must contain carbohydrates.

To explain in more detail: some early studies showed no benefit from carnitine because they failed to adequately increase muscle carnitine levels. This was primarily because the supplement was not taken at the right time, when insulin levels would be elevated and muscle absorption would be adequate.

Recent research shows that insulin levels must be high for adequate amounts of L-carnitine to enter muscle cells, where it does most of its work. On the other hand, taking L-carnitine enhances insulin's actions in muscle cells, helping deliver more glucose and L-carnitine to muscle cells.

While just 1 gram of L-carnitine can be effective, your best bet is to take 2-3 grams per serving for maximum benefit, along with at least 30-40 grams of carbohydrates and 20-30 grams of protein, which can be done with a solid meal or shake with protein powder and carbohydrate powder (such as maltodextrin or dextrose).

At this point, based on current literature, it appears there is no need to cycle L-carnitine . If taken regularly (without interruption), it should remain effective long-term.

Some studies report breath and sweat with a “fishy” odor after L-carnitine supplementation, which is likely due to the formation of byproducts from the metabolism of L-carnitine.

Dry mouth and gastrointestinal discomforthave also been reported in some studies using L-carnitine, while gastrointestinal problems (including nausea and stomach discomfort) are a common adverse effect of some forms of carnitine.

However, several meta-analyses conclude that L-carnitine and its derivatives are generally safe and well-tolerated. Their side effects are mostly uncomfortable but harmless symptoms.

Furthermore, supplementation of approximately 2,000 milligrams (mg) per day is considered safe for human consumption. Some human studies have even used L-carnitine doses as high as 6,000 mg/day without serious side effects, but a full safety evaluation with further studies is still needed.

L-carnitine is often promoted as a weight-loss and fat-burning supplement, primarily due to its role in fat metabolism. As mentioned, it helps transport fats into the cells' mitochondria, where they are burned for energy.

This action can theoretically promote fat burning and, consequently, weight loss, especially when combined with physical exercise.

A review of 37 studies found that L-carnitine supplementation significantly reduced fat mass. However, it had no effect on abdominal fat or body fat percentage.

Another analysis of nine studies — mostly in obese or elderly individuals — found that people lost an average of 1.3 kilograms (2.9 pounds) more weight when taking L-carnitine.

Additionally, a meta-analysis of six studies showed that L-carnitine could reduce body weight, BMI, and abdominal fat in people with polycystic ovary syndrome.

It's important to emphasize that L-carnitine supplementation alone isn't a magic solution for weight loss. Sustainable fat burning involves regular exercise and a proper diet.