L-Carnitine: Uses, Benefits, Side Effects, and Dosage

I Thought Whey Protein is the Best for Recovery?

Post workout nutrition

Well, you are not wrong!

The thing is, I don’t consider protein powders a supplement; I consider them food.

Just like butter or heavy cream are not milk fat supplements, whey is not a milk protein supplement.

Yes, there are numerous protein supplements, and it is likely that protein powders are the most popular supplements in the US and the world, but let me ask you, how do you get most of your protein?

I hope that more than half of your protein comes from whole food. I want to take that a step further. I hope that more than at least three-quarters of your protein intake comes from food (and we sell protein powder!).

With that consideration, if you’re eating 125g of protein per day and 25g comes as a whey protein shake, but 100g comes from food, you’re not really relying on that dietary “supplement.”

It’s certainly helping, but you’re using it to replace food. It’s easy. It’s convenient. It’s food – convenient, easy food with some advantages and some disadvantages.

The process to obtain whey protein isn’t even all that complicated – people do it in their homes!

It involves putting clabbered milk or yogurt in a cheesecloth and letting the whey drip into a bowl.

If you want it as a powder, put it in a dehydrator then blend up the chunks of protein in a blender. That’s it. Seriously. Food. Crazy, right?

What is l-carnitine

why am i sore after exercise

Now that that’s settled.

The single best supplement for exercise recovery is carnitine.

Carnitine is available from foods, however, one would need to eat about 80oz of beef (richest source of carnitine) per day to get an efficacious dose of carnitine (which is why it’s a supplement!).

L carnitine benefits

Carnitine is popular with bodybuilders because it’s purported to enhance fat loss.

From a biochemistry perspective, this makes sense.

Carnitine is an amino acid derivative, so it is kind of like protein (it is not an amino acid, but similar).

Carnitine’s similarity to protein does not stop there.

Its primary bodily function is to form carnitine palmitoyltransferase (palm-it-o-eel-trans-fur-ace) – an enzyme that transports fatty acids into the mitochondria for oxidation, or a “fat burner,” if you will (1).

However, carnitine’s ability to actually reduce body fat mass may be limited to older folks who likely already have compromised carnitine intake, absorption, or insufficient carnitine palmitoyltransferase activity (2, 3).

In younger individuals with obesity beginning a regular exercise program (4 days per week of light aerobics), daily carnitine did not influence weight loss (4).

Although, it is worth mentioning that none of the participants lost weight or body fat over the 8 weeks, which means that the results of this study could be confounded by an inadequate weight loss stimulus that did not take advantage of potentially enhanced body fat metabolism.

Another study examined L-Carnitine L-Tartrate in a different context that suggests it is effective in the prevention of body fat accumulation, which is why it may be a favorite for bodybuilders.

Young men consumed either 80g of carbohydrate (placebo) or 80g of carbohydrate + 2g of L-Carnitine L-Tartrate twice a day for 12 weeks (5). The placebo group gained 1.8 kg of body fat, but the group receiving carnitine had no change in body fat mass, suggesting carnitine may be useful during a period of increased energy (calorie) intake.

At face value, the endurance athlete may not find the effects of carnitine on body composition particularly interesting but think about it this way.

You can eat an extra 160 grams of carbohydrate (640 Calories) every day, make sure muscle glycogen is topped off and you have plenty of fuel to run, bike, swim, lift, or do other exercise and have NO CHANGE in your body weight.

That s#!t sounds like magic, but its mechanisms were supported by analysis of muscle biopsies and genetic expression.

And that’s not even the major reason why we like carnitine.

Carnitine may also:

  • enhance blood glucose absorption (more sugar gets to the muscle, where it belongs)
  • combat increases in oxidative stress and free radicals
  • enhance blood flow (better nutrient delivery – faster recovery)
  • reduce fatigue
  • repair muscle damage
  • enhance natural hormone function
  • enhance aerobic and anaerobic performance.

Let’s dive in!

Carnitine Helps Athletes Recover from Exercise

supplement to help running soreness

Recovery from exercise is a two-headed monster.

From pretty much any type of exercise that will enhance performance, recovering from inflicted muscle damage will be required before the next training session

This applies to virtually all athletes including all walks of endurance athletes, hybrid athletes, aesthetic athletes, team sport athletes, and weight lifting athletes.

For athletes with busy training schedules and/or those that train the same muscle group back-to-back days (e.g., runners are always training their legs), recovering muscle glycogen burned during exercise is also imperative if the athlete wants to have a good training session (or two) the next day.

Carnitine fights both heads of this monster at the same time.

Carnitine Reduces Muscle Soreness and Helps Repair Muscle Damage

how to be not sore after working out

One of the ways we know that active muscles benefit from carnitine supplementation is by the observation that carnitine supplementation reduces ammonia excreted after exercise.

Ammonia is produced from the breakdown of proteins.

During exercise, some muscle proteins are broken down to obtain fuel (ATP), similar to how the body breaks down carbohydrates and fats to make energy (also ATP).

How to take l carnitine

Supplementation with 2g of L-Carnitine L-Tartrate per day reduces ammonia excretion by ~20% during 90 minutes of exercise at 70% VO2Max while carbohydrate oxidation was increased after 90 minutes of cycling but not to a degree of statistical significance (6).

This is very important for endurance athletes who need to save the muscle function of their legs for every day of training.

Before we can talk about muscle damage, we have to talk about some of the pitfalls of research.

One of the tricky parts of formulating a good supplement is not using ingredients that cause the athlete to “shoot themselves in the foot.”

Supplements like green tea and others appear to benefit the athlete at a glance, but in reality, the athlete is reducing their capacity for exercise, which will ultimately lead to poor performance.

This is because the ultimate driver of enhanced performance is the training!

Nutrition and supplementation strategies need to be designed to support the training – they don’t do much on their own.

However, unfortunately, lower quality supplements that do not prioritize the science don’t make this consideration.

Therefore, we want a recovery supplement to enhance repair, NOT prevent damage.

This is very important, so we’ll say it again.

Recovery supplements should enhance muscle repair, not prevent muscle damage.

More importantly, we must consider the exception. If the recovery supplement also increases maximal performance, less muscle damage in response to submaximal exercise can be disregarded.

In other words, less muscle damage during submaximal exercise + no improvement in maximal performance = BAD.

Less muscle damage during submaximal exercise + improvement in maximal performance = GOOD.

This is because muscle damage provides a catalyst for improvement, we adapt to muscle damage, which makes us better athletes. Remember the first rule. The ultimate driver of enhanced performance is the training.

Ok, now let’s talk about carnitine and muscle damage.

In resistance-trained men, 3 weeks of L-carnitine supplementation accelerated the healing process following a bout of squats.

In the immediate aftermath of the exercise bout, plasma markers of muscle damage increased in both groups. One of the markers, myoglobin, were not different the day after exercise, but the group that supplemented L-Carnitine had reductions in myoglobin 2-4 days after the exercise bout compared to greatly increased levels on day 2 and elevated levels on days 3-4 in placebo.

Another marker, MDA (malondialdehyde), returned to baseline values quicker in those supplementing L-Carnitine, and creatine kinase, which only increases days after infliction of muscle damage, only increased in placebo on days 2-4 after the exercise bout.

When the muscle tissue was assessed by MRI on days 3 and 6 post exercise, the carnitine group had half the amount of muscle damage as the placebo group.

Those receiving L-Carnitine reported less perceived muscle soreness during all 4 days post exercise (7).

These observations are supported by other studies (8-11). Moreover, carnitine supplementation has increase endurance performance in at least six studies (10, 12-16) and increased cycle sprint performance in at least two studies (17, 18).

When to take l carnitine

supplement for muscle soreness

For at least 2 hours following exercise, our muscles are extra sensitive to the nutrients we put in our body.

Consuming carbohydrates post exercise greatly increases the amount of carbohydrate muscles are able to absorb.

In healthy, lean males, L-Carnitine L-Tartrate supplementation increased insulin sensitivity in response to an oral glucose tolerance test.

After ingesting 75g of glucose, participants showed more efficient blood glucose clearance in response to an equal amount of insulin released following 2 weeks of daily carnitine supplementation (19).

Remember the study we talked about earlier? The one that had magic s#!t? Let’s talk about the muscle biopsies and genetic expression results a little (5).

Supplementing carnitine increased muscle carnitine content by 21%.

The increase in muscle carnitine content caused a change in the expression of different genes relating to key metabolic enzymes including those in the insulin signaling, peroxisome proliferator-activated receptor, and fatty acid metabolism pathways.

Specifically, as it pertains to carbohydrate metabolism and insulin signaling, 22 genes were upregulated by carnitine.

This is especially interesting when recalling that these participants overate by over 600 calories as carbohydrates per day, but carnitine totally prevented any weight gain, as the typical individual would begin to have decreased insulin sensitivity and glucose clearance.

If you’re thinking that you, as an athlete, are immune from decreased insulin sensitivity as a result of eating necessary amounts of carbohydrate, think again.

Consuming enough carbohydrate post exercise (when we can BETTER tolerate carbs) to replace the carbs burned during exercise reduces insulin resistance into the next morning (20).

Other Cool Effects of Carnitine

best recovery protein

Briefly, carnitine supplementation has been found to improve endothelial function, which results in increased nitric oxide and blood flow.

In healthy, active participants, supplementing with carnitine for 3 weeks improved their vasodilatory response to vascular occlusion (21).

Vascular occlusion occurs fairly often during exercise, particularly during resistance exercise, and blood flow is exceedingly important for clearing built up metabolic byproducts like lactate and bringing in fresh oxygen and glucose that at least indirectly influence recovery.

Carnitine supplementation reduces markers of oxidative stress at rest, but does not impede the oxidative stress response to exercise (7).

These observations were also reported by Bloomer and Smith (22). This is important because training is the ultimate stimulus.

We don’t want to interfere with the stress response to training.

However, reducing oxidative stress and free radicals at rest or in the days following exercise is definitely beneficial for athletes’ recovery.

The faster an athlete can recover, the faster than can engage in the ultimate stimulus again!

Carnitine supplementation may also facilitate hormonal activities in men.

Testosterone and insulin-like growth factor (IGF) are well-known, naturally-present hormones that improve recovery.

A study previously described (7) also looked at these markers.

They observed increased levels of IGFBP3, which ultimately leads to increased action of IGF.

In conjunction with this mechanism, the authors, which measured muscle tissue disruption by MRI, propose that greater quantities of intact muscle maintain greater ability to bind IGF and testosterone at their muscular receptors, further promoting muscle protein synthesis and recovery from exercise.

How Much of What Types of Carnitine?

best type of supplement for muscle soreness

You can see why carnitine is the best supplement for post workout recovery.

Now for the details on supplementation. In the large majority of studies described above, carnitine is supplemented as L-Carnitine L-Tartrate in doses of 2 grams per day.

Other forms of carnitine include Acetyl L-Carnitine, which also functions as a nootropic brain booster, glycine propionyl-L-Carnitine, which is used for clinical applications, or levocarnitine, which is not common.

L-Carnitine L-Tartrate is the most applicable for sports performance and recovery.

Some studies have used doses of carnitine equal to 3 grams per day, and one study went all the way up to 15 grams. However, 2 grams has consistently been shown as efficacious.

This is precisely why RecoverElite contains 2 grams of L-Carnitine L-Tartrate per serving.

It is a perfect companion for an optimal 4:1 ratio of carbohydrate to protein fortified with L-Leucine to maximize recovery. L-Carnitine L-Tartrate supplemented with the post workout carbs found in RecoverElite further enhances the absorption and efficacy of L-Carnitine L-Tartrate (5).

Simultaneously, the carnitine helps maintain proper glucose absorption and utilization at the muscular level while accelerating muscle tissue recovery to get you back on your feet faster than ever!

If you’re looking for a single ingredient to enhance your post-workout recovery, look no further than L-Carnitine L-Tartrate. If you want the total package with carbs, protein, carnitine, and more, RecoverElite is the best supplement to improve post-workout recovery.

  1. McGarry, J. D., & Brown, N. F. (1997). The mitochondrial carnitine palmitoyltransferase system—from concept to molecular analysis. The FEBS Journal, 244(1), 1-14.
  2. Pistone, G., Marino, A. D., Leotta, C., Dell’Arte, S., Finocchiaro, G., & Malaguarnera, M. (2003). Levocarnitine administration in elderly subjects with rapid muscle fatigue. Drugs & aging, 20(10), 761-767.
  3. Malaguarnera, M., Cammalleri, L., Gargante, M. P., Vacante, M., Colonna, V., & Motta, M. (2007). l-Carnitine treatment reduces severity of physical and mental fatigue and increases cognitive functions in centenarians: a randomized and controlled clinical trial–. The American journal of clinical nutrition, 86(6), 1738-1744.
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  5. Stephens, F. B., Wall, B. T., Marimuthu, K., Shannon, C. E., Constantin‐Teodosiu, D., Macdonald, I. A., & Greenhaff, P. L. (2013). Skeletal muscle carnitine loading increases energy expenditure, modulates fuel metabolism gene networks and prevents body fat accumulation in humans. The Journal of physiology, 591(18), 4655-4666.
  6. Broad, E. M., Maughan, R. J., & Galloway, S. D. (2008). Carbohydrate, protein, and fat metabolism during exercise after oral carnitine supplementation in humans. International journal of sport nutrition and exercise metabolism, 18(6), 567-584.
  7. Volek, J. S., Kraemer, W. J., Rubin, M. R., Gómez, A. L., Ratamess, N. A., & Gaynor, P. (2002). L-Carnitine L-tartrate supplementation favorably affects markers of recovery from exercise stress. American Journal of Physiology-Endocrinology and Metabolism, 282(2), E474-E482.
  8. Spiering, B. A., Kraemer, W. J., Hatfield, D. L., Vingren, J. L., Fragala, M. S., Ho, J. Y., ... & Volek, J. S. (2008). Effects of L-carnitine L-tartrate supplementation on muscle oxygenation responses to resistance exercise. The Journal of Strength & Conditioning Research, 22(4), 1130-1135.
  9. Ho, J. Y., Kraemer, W. J., Volek, J. S., Fragala, M. S., Thomas, G. A., Dunn-Lewis, C., ... & Maresh, C. M. (2010). l-Carnitine l-tartrate supplementation favorably affects biochemical markers of recovery from physical exertion in middle-aged men and women. Metabolism-Clinical and Experimental, 59(8), 1190-1199.
  10. Fatouros, I. G., Douroudos, I., Panagoutsos, S., Pasadakis, P., Nikolaidis, M. G., Chatzinikolaou, A., ... & Taxildaris, K. (2010). Effects of L-carnitine on oxidative stress responses in patients with renal disease. Medicine and science in sports and exercise, 42(10), 1809-1818.
  11. Kraemer, W. J., Volek, J. S., French, D. N., Rubin, M. R., Sharman, M. J., Gomez, A. L., ... & Hakkinen, K. (2003). The effects of L-carnitine L-tartrate supplementation on hormonal responses to resistance exercise and recovery. The Journal of Strength & Conditioning Research, 17(3), 455-462.
  12. Cha, Y. S., Choi, S. K., Suh, H., Lee, S. N., Cho, D., & Lim, K. (2001). Effects of carnitine coingested caffeine on carnitine metabolism and endurance capacity in athletes. Journal of nutritional science and vitaminology, 47(6), 378-384.
  13. Dragan, G.I.; Wagner, W.; Ploesteanu, E. Studies concerning the ergogenic value of protein supply and L-carnitine in elite junior cyclists. Physiologie 1988, 25, 129–132.
  14. Dragan, I.G.; Vasiliu, A.; Georgescu, E.; Eremia, N. Studies concerning chronic and acute effects of L-carnitine in elite athletes. Physiologie 1989, 26, 111–129.
  15. Wall, B. T., Stephens, F. B., Constantin‐Teodosiu, D., Marimuthu, K., Macdonald, I. A., & Greenhaff, P. L. (2011). Chronic oral ingestion of l‐carnitine and carbohydrate increases muscle carnitine content and alters muscle fuel metabolism during exercise in humans. The Journal of physiology, 589(4), 963-973.
  16. Orer, G. E., & Guzel, N. A. (2014). The effects of acute L-carnitine supplementation on endurance performance of athletes. The Journal of Strength & Conditioning Research, 28(2), 514-519.
  17. Jacobs, P. L., Goldstein, E. R., Blackburn, W., Orem, I., & Hughes, J. J. (2009). Glycine propionyl-L-carnitine produces enhanced anaerobic work capacity with reduced lactate accumulation in resistance trained males. Journal of the International Society of Sports Nutrition, 6(1), 9.
  18. Vecchiet, L., Di Lisa, F., Pieralisi, G., Ripari, P., Menabo, R., Giamberardino, M. A., & Siliprandi, N. (1990). Influence of L-carnitine administration on maximal physical exercise. European journal of applied physiology and occupational physiology, 61(5-6), 486-490.
  19. Galloway, S. D., Craig, T. P., & Cleland, S. J. (2011). Effects of oral L-carnitine supplementation on insulin sensitivity indices in response to glucose feeding in lean and overweight/obese males. Amino acids, 41(2), 507-515.
  20. Taylor, H. L., Wu, C. L., Chen, Y. C., Wang, P. G., Gonzalez, J. T., & Betts, J. A. (2018). Post-Exercise Carbohydrate-Energy Replacement Attenuates Insulin Sensitivity and Glucose Tolerance the Following Morning in Healthy Adults. Nutrients, 10(2), 123.
  21. Volek, J. S., Judelson, D. A., Silvestre, R., Yamamoto, L. M., Spiering, B. A., Hatfield, D. L., ... & Kraemer, W. J. (2008). Effects of carnitine supplementation on flow-mediated dilation and vascular inflammatory responses to a high-fat meal in healthy young adults. American Journal of Cardiology, 102(10), 1413-1417.
  22. Bloomer, R. J., & Smith, W. A. (2009). Oxidative stress in response to aerobic and anaerobic power testing: influence of exercise training and carnitine supplementation. Research in Sports Medicine, 17(1), 1-16.

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