L-Carnitine (carnitine) is an essential, non-toxic, natural nutrient that helps burn fat for fuel by transporting fatty acids into the mitochondria – our internal power plants – to produce energy. 

How Carnitine works

Carnitine has an essential role in transporting fat into mitochondria (the furnace of the cell). Therefore, carnitine has been marketed as a fat burning supplement. In two separate studies performed 10 years ago, supplementation of carnitine (3g per day) for 10 days resulted in significantly higher rates of fat oxidation. This work was recently validated by researchers in the UK who studied two groups of healthy endurance-trained men.

CarnitineThe control group drank an 80g carbohydrate-only beverage two times per day for 24 weeks. The test group received 2g of L-Carnitine (in the form of L-Carnitine L-Tartrate) with their 80g carb beverage for the same dosage period. In the L-Carnitine group, resting muscle carnitine was unchanged after 12 weeks, but increased by 21% after 24 weeks. When the L-Carnitine group exercised at a low intensity after 24 weeks of supplementation, they showed that the higher muscle carnitine was linked to significant muscle glycogen sparing (55% better) compared to the control group. Also, work output was 35% greater than the control group.

Source: Jeff S. Volek Ph.D., R.D.

Carnitine boosts recovery

As well as its fat burning benefits, Carnitine also boosts recovery. Although more than 95% of the body’s total carnitine pool resides in skeletal muscle, several lines of evidence support a role of carnitine in other processes beyond fat burning.

There are two notable studies: in the first, healthy men who supplemented with carnitine (2g per day for 3 weeks) showed significantly less accumulation of markers of post-exercise stress, including less formation of free radicals, and less tissue damage and muscle soreness after moderate intensity squat exercises. In the second follow-up study, healthy men performed a resistance exercise challenge that included five sets of squat exercise on three separate occasions. For three weeks prior to each test, subjects ingested either 1g of L-Carnitine per day, 2g per day or a placebo. The second study confirmed that carnitine supplementation was effective at reducing the acute response of several markers of biochemical stress after resistance exercise. In addition, perception of muscle soreness was lower after exercise with carnitine supplementation.

In a third study on an older group (aged 40 to 65) carnitine supplementation was found to be beneficial when examining post-exercise markers of metabolic stress, muscle disruption, and muscle soreness in middle-age men and women.

Overall taking Canitine led to better recovery from exercise, decreased exercise-induced muscle damage, decreased muscle soreness, increased antioxidant effects, and improved vascular function. The most effective dose in these studies was 1-2g per day.

Types of Carnitine

You can get Carnitine from foods, or you can take supplements. The best sources are red meat and dairy products. There is carnitine in other food sources, but this is much lower – such as nuts and seeds (e.g. pumpkin, sunflower, sesame), legumes or pulses (beans, peas, lentils, peanuts), vegetables (artichokes, asparagus, beet greens (young leaves of the beetroot), broccoli, brussels sprouts, collard greens, garlic, mustard greens, okra, parsley, kale), fruits (apricots, bananas), cereals (buckwheat, corn, millet, oatmeal, rice bran, rye, whole wheat, wheat bran, wheat germ) and other foods (bee pollen, brewer’s yeast, carob). There is 95mg of Carnitine in beef steak, compared to e.g. 0.195 mg in asparagus.

Carnitine can be purchased in various forms including L-Carnitine L-Tartrate, L-Carnitine (free form), and Acetyl-L-Carnitine. All of these types can deliver adequate amounts of carnitine to the blood. However, if it is taken for cognitive benefits, Acetyl L-Carnitine is recommended as this can be transported more easily to the brain.

As with all supplements, it is recommended that you speak to a healthcare professional or your doctor before taking them. This is to ensure that they are right for you and your body.

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