L-carnitine for athletes: what is needed for

L-carnitine for athletes: a comprehensive guide to use and action mechanisms

I. The role of L-carnitine in energy exchange: from the molecular level to physical activity

1. Fundamental chemistry and biosynthesis L-carnitine:

   • L-carnitine (β-hydroxy-γ-trimethylaminobutirate) is a vitamin-like substance that plays a critical role in energy metabolism, especially in the transportation of fatty acids through the internal mitochondria membrane, where they are oxidized (β-oxidation) for energy production.
   • The molecular structure of the L-carnitine consists of butyrate nucleus with hydroxyl and trimethylamonium groups. L-form is a biologically active isomer.
   • The endogenous synthesis of L-carnitine occurs in the liver, kidneys and brain of two essential amino acids: lysine and methionine. This process requires the participation of several vitamins, including vitamin C, vitamin B6, niacin and iron. The disadvantage of any of these nutrients can lead to L-carnitine deficiency.
   • The main stages of biosynthesis:
     1. Lizin methylation with the formation of ε-n-trimetillizin.
     2. Hydroxylating ε-n-trimetillizin with the formation of β-hydroxy-am-trimetillizin.
     3. The breakdown of β-hydroxy-force-trimetillizin with the formation of γ-butybutaine.
     4. Hydroxylation of γ-butybutaine with the formation of L-carnitine.
   • The genetic defects of enzymes involved in the L-carnitine biosynthesis can lead to primary carnitine deficiency.

2. Transport of fatty acids and β-oxidation:

   • L-carnitine is a key component of the cornitin shuttle system, which is necessary for transferring long-chain fatty acids (LCFA) from cytosol into mitochondria, where β-oxidation occurs.
   • LCFA cannot directly penetrate through the internal mitochondrial membrane. Carnetine shuttle consists of three main enzymes:
     1. Carnitin-Palmitrailtransferase I (CPT I): located on the external mitochondrial membrane and catalyzes the reaction of LCFA accession to cornitin, forming acil-carnitine. This process is inhibited by a low-line-COA, which regulates the flow of fatty acids in mitochondria depending on the energy status of the cell.
     2. Carnitin Acillers Translock (CACT): Located on the internal mitochondrial membrane and exchange Acil-Carnitine for free cornitine through the membrane.
     3. Carnitin-PalmitoilTransferase II (CPT II): located on the internal mitochondrial membrane and catalyzes the reverse reaction by removing LCFA from carnitine, freeing LCFA inside the mitochondria for β-oxidation and regenerating free carnitine.
   • β-oxidation is a metabolic process, during which fatty acids are split into acetyl-Coa, which is then entered into the Crebs cycle (citric acid cycle) for energy production in the form of ATP (adenosineurphosphate).
   • The effectiveness of β-oxidation depends on the presence of a sufficient amount of L-carnitine. L-carnithine deficiency leads to a violation of fatty acid transport in mitochondria and, therefore, to a decrease in energy production from fats.

3. L-carnitine and glucose metabolism:

   • L-carnitine can also affect glucose metabolism, albeit less directly than the metabolism of fatty acids.
   • It can improve insulin sensitivity, which contributes to more efficient use of glucose cells. The mechanism of this action is probably associated with the influence of L-carnitine on lipid metabolism and a decrease in the accumulation of intracellular lipids, which can lead to insulin resistance.
   • Some studies show that L-carnitine can increase glycogen reserves in the muscles, which can be useful for athletes involved in endurance sports.
   • It can also reduce the level of lactate in the muscles during intense exercises, which can improve performance and reduce muscle fatigue. This may be due to an improvement in oxidative metabolism and a decrease in dependence on anaerobic glycolysis.

4. L-carnitine as an antioxidant and neuroprotector:

   • L-carnitine has antioxidant properties and can protect cells from damage caused by free radicals.
   • During intensive exercises, the formation of free radicals increases, which can lead to oxidative stress and damage to muscle cells. L-carnitine can reduce oxidative stress, neutralizing free radicals and maintaining the antioxidant protection of the body.
   • It can also have a neuroprotective effect, protecting the nerve cells from damage. This is due to its ability to improve energy metabolism in nerve cells and reduce oxidative stress.
   • Acetyl-L-carnitine (alcar), L-carnitine ether, is especially effective as an antioxidant and a neuroprotector. It penetrates more easily through a hematoencephalic barrier and can have a more pronounced effect on the brain.

II. L-carnitine and sport: Advantages and use in various sports

1. L-carnitine to improve physical endurance:

   • The main advantage of L-carnitine for athletes is associated with its ability to increase the use of fats as a source of energy, which can improve physical endurance.
   • In prolonged aerobic loads (for example, running long distances, swimming, cycling), the body uses both carbohydrates and fats as fuel. L-carnitine can contribute to the switching of metabolism to the use of fats, which allows you to maintain glycogen reserves and extend the time before fatigue.
   • Some studies show that the intake of L-carnitine can increase VO2MAX (maximum oxygen consumption), which is an important indicator of physical endurance.
   • He can also reduce fatigue and accelerate recovery after training.

2. L-carnitine for power sports and a set of muscle mass:

   • Although L-carnitine is primarily associated with aerobic sports, it can also be useful for athletes involved in strength sports and striving for a set of muscle mass.
   • It can help reduce damage to muscle cells after intense training, which can accelerate restoration and promote muscle growth.
   • Some studies show that L-carnitine can increase the level of testosterone, hormone, which plays an important role in muscle growth and restoration.
   • It can also improve insulin sensitivity, which contributes to better absorption of nutrients and muscle growth.
   • L-carnitine can have an indirect effect on a set of muscle mass by improving energy metabolism and decreasing fatigue, which allows you to train more intensively and effectively.

3. L-carnitine for weight loss and fat burning:

   • L-carnitine is often used as an additive to reduce weight and fat burning, since it helps to increase the use of fats as a source of energy.
   • It helps to transport fatty acids to mitochondria, where they oxidize and turn into energy. This can lead to a decrease in fat reserves in the body.
   • However, it is important to note that L-carnitine is not a «miracle tool» for weight loss. It is most effective in combination with a healthy diet and regular physical exercises.
   • Some studies show that the intake of L-carnitine can increase the rate of metabolism and improve the composition of the body, reducing the percentage of fat and increasing the percentage of muscle mass.

4. L-carnitine and recovery after training:

   • L-carnitine plays an important role in recovery after training, reducing damage to muscle cells and oxidative stress.
   • It can reduce the level of muscle damage markers, such as creatinkinase (CK) and lactate dehydrogenase (LDH), which indicates less muscle damage.
   • It can also reduce muscle soreness (DOMS — Delayed ONSET MUSCLE SORENESS), which often occurs after intense training.
   • L-carnitine can improve muscle blood supply, which contributes to the better intake of nutrients and oxygen, accelerating recovery.

5. L-carnitine in various sports:

   • Aerobic sports (running, swimming, cycling): Improving endurance, increasing the use of fats as a source of energy, decreased fatigue.
   • Strength sports (heavy athletics, powerlifting, bodybuilding): Reducing muscle damage, acceleration of recovery, a possible increase in testosterone levels, improving insulin sensitivity.
   • Team sports (football, basketball, hockey): Improving endurance, decreased fatigue, acceleration of recovery between training and games.
   • Types of sport on endurance and strength (triathlon, crossfit): The combination of advantages for aerobic and power performance.

III. Forms of L-carnitine: comparison and choice of optimal shape for athletes

1. L-carnitin L-Tarrate (LCLT):

   • LCLT is one of the most common forms of L-carnitine used in sports additives.
   • It is a compound of L-carnitine with L-cininal acid, which improves its absorption and bioavailability.
   • LCLT is often used to improve recovery after training, reduce muscle pain and reduce muscle damage.
   • It can also improve the hormonal profile, increasing the level of testosterone and reducing the level of cortisol.

2. Acetyl-L-carnitine (Alcar):

   • Alcar is an acetylated form of L-carnitine, which penetrates the hematoencephalic barrier easier.
   • It has neuroprotective and antioxidant properties, improves cognitive functions and reduces fatigue.
   • Alcar can improve the mood, concentration and memory, which can be useful for athletes who need high concentration and coordination.
   • It can also improve energy metabolism in nerve cells and reduce oxidative stress.

3. Propionil-L-carnitine (GPLC):

   • The GPLC is a L-carnitine compound with the propionil group.
   • It has antioxidant and vasodilative properties, improves the blood supply to the muscles and reduces blood pressure.
   • GPLC can improve physical endurance, reduce fatigue and accelerate recovery after training.
   • It can also improve erectile function and reduce the symptoms of intermittent chromium.

4. L-Carnitin Fumile:

   • L-carnitine fumarat is a compound of L-carnitine with fumaric acid.
   • Fumaric acid is an intermediate product of the Crebs cycle and plays an important role in the production of energy.
   • L-Carnitin Fumarat can improve energy metabolism and reduce fatigue.
   • It can also have an antioxidant effect and protect the cells from damage caused by free radicals.

5. The choice of optimal shape:

   • The choice of optimal form of L-carnitine depends on the specific goals and needs of the athlete.
   • To improve recovery after training and reduce muscle pain, LCLT is recommended.
   • To improve cognitive functions and reduce fatigue, Alcar is recommended.
   • To improve the blood supply to the muscles and reduce blood pressure, GPLC is recommended.
   • To improve energy metabolism and reduce fatigue, L-carnitine fumarat is recommended.
   • Some athletes can use a combination of various forms of L-carnitine to achieve the maximum effect.

IV. Dosage and method of using L-carnitine for athletes

1. Recommended dosage:

   • The recommended dosage of L-carnitine for athletes varies depending on the shape, goals and individual characteristics of the body.
   • It is usually recommended to take from 500 mg to 3000 mg L-carnitine per day, divided into several tricks.
   • For LCLT, the recommended dosage is from 1000 mg to 3000 mg per day.
   • For Alcar, the recommended dosage is from 500 mg to 2000 mg per day.
   • For GPLC, the recommended dosage is from 500 mg to 1500 mg per day.
   • For L-carnitine fumarat, the recommended dosage is from 500 mg to 2000 mg per day.
   • Some athletes can experiment with higher doses, but it is important to start with low doses and gradually increase them in order to avoid side effects.

2. Reception time:

   • The time of taking L-carnitine can also affect its effectiveness.
   • Reception of L-carnitine before training can improve endurance and increase the use of fats as a source of energy.
   • Reception of L-carnitine after training can accelerate recovery and reduce muscle pain.
   • The intake of L-carnitine with food containing carbohydrates can improve its absorption. Insulin stimulates L-carnitine transport to muscle cells.
   • Some athletes prefer to take L-carnitine in the morning on an empty stomach to improve energy metabolism.

3. Methods of application:

   • L-carnitine is available in various forms, including capsules, tablets, powders and liquids.
   • Capsules and tablets are conveniently taken, but they can be more slowly absorbed than powders and liquids.
   • Powers can be dissolved in water or juice and take before or after training.
   • The liquids are quickly absorbed and can be added to sports drinks.
   • The choice of form L-carnitine depends on personal preferences and ease of use.

4. Combining with other additives:

   • L-carnitine can be combined with other sports additives to enhance its effect.
   • Creatine and L-carnitine can improve strength performance and a set of muscle mass.
   • BCAA (amino acids with an extensive chain) and L-carnitine can accelerate recovery after training and reduce muscle pain.
   • Caffeine and L-carnitine can improve endurance and increase the use of fats as a source of energy.
   • It is important to consult a doctor or sports nutritionist before combining L-carnitine with other additives.

5. Duration of admission:

   • L-carnitine can be taken both shortly (for example, before competitions) and for a long time (for example, for several months).
   • Long-term reception of L-carnitine can improve its effectiveness and lead to more pronounced results.
   • It is recommended to take breaks in taking L-carnitine every few months to avoid getting used to the body.
   • It is important to monitor the reaction of the body to L-carnitine and adjust the dosage and duration of administration in accordance with individual needs.

V. Safety and side effects of L-carnitine

1. L-carnitine safety:

   • L-carnitine is considered a relatively safe addition subject to the recommended dosages.
   • Numerous studies have shown that L-carnitine does not have serious side effects in most people.
   • However, like any other additive, L-carnitine can cause side effects in some people.

2. Possible side effects:

   • The most common side effects of L-carnitine include:
     • Gastrointestinal disorders (nausea, vomiting, diarrhea, abdominal pain).
     • The unpleasant smell of the body (fish smell).
     • Insomnia.
     • Charp heartbeat.
   • These side effects usually occur with high doses of L-carnitine (more than 3000 mg per day).
   • Rarely L-carnitine can cause allergic reactions.

3. Contraindications:

   • L-carnitine is contraindicated to people with:
     • Individual intolerance to L-carnitine.
     • Severe kidney diseases.
     • Hypothyroidism (reduced thyroid function).
     • Epilepsy.
   • Pregnant and lactating women should consult a doctor before taking L-carnitine.

4. Interaction with drugs:

   • L-carnitine can interact with some drugs, such as:
     • Anticoagulants (warfarin).
     • Preparations for the thyroid gland.
     • Valproic acid.
   • It is important to inform the doctor about all the drugs taken before taking L-carnitine.

5. Recommendations for safe use:

   • Start with low doses of L-carnitine and gradually increase them to evaluate tolerance.
   • Take L-carnitine with food to reduce the risk of gastrointestinal disorders.
   • Do not exceed the recommended dosage.
   • Follow the body’s reaction to L-carnitine and stop taking side effects.
   • Consult a doctor or sports nutritionist before taking L-carnitine, especially if you have any diseases or you take medications.

VI. Research and scientific data on the effectiveness of L-carnitine in sports

1. Review of clinical research:

   • Numerous clinical studies studied the effectiveness of L-carnitine in sports.
   • Some studies have shown that L-carnitine can improve physical endurance, increase the use of fats as a source of energy, reduce fatigue and accelerate recovery after training.
   • Other studies have not identified significant advantages of L-carnitine.
   • Research results can vary depending on the form of L-carnitine, dosage, duration of reception, sport and individual characteristics of the body.

2. Meta-analyzes and systematic reviews:

   • Met-analyzes and systematic reviews combine the results of several studies to assess the overall efficiency of L-carnitine.
   • Some meta-analyzes have shown that L-carnitine can have a positive effect on physical endurance, body composition and recovery after training.
   • However, it must be borne in mind that the quality of research can vary, and some studies may have methodological disadvantages.

3. Key research results:

   • Improvement of endurance: Some studies have shown that L-carnitine can increase the time before fatigue on aerobic loads.
   • Increased use of fats: L-carnitine can contribute to the switching of metabolism to the use of fats as a source of energy, which can be useful for athletes involved in endurance sports.
   • Decrease in fatigue: L-carnitine can reduce fatigue and improve recovery after training.
   • Reducing muscle damage: L-carnitine can reduce the level of muscle damage markers, such as creatinkinase (CK) and lactate dehydrogenase (LDH).
   • Improving the composition of the body: Some studies have shown that L-carnitine can reduce the percentage of fat and increase the percentage of muscle mass.
   • Improving cognitive functions: Alcar can improve mood, concentration and memory.

4. Prospects for future research:

   • Additional studies are needed to confirm the effectiveness of L-carnitine in sports and determine the optimal dosages and methods of application for various sports and individual characteristics of the body.
   • Future studies should be focused on studying the mechanisms of action of L-carnitine and its interaction with other nutrients and additives.
   • It is necessary to carry out better and large -scale clinical studies using standardized protocols and assessment methods.

VII. Conclusion (not included, as indicated in the task)

VIII. List of literature (not included, as indicated in the task)