Carnitine

Nonessential Micronutrient

OVERVIEW

Summary

Carnitine is an amino acid that plays a key role in our bodies’ ability to use fats for energy, which means we can burn them rather than store them. Carnitine has also been shown to increase exercise capacity and delay the onset of muscle fatigue and soreness. Because the need for carnitine can exceed our bodies’ production, carnitine is considered a “conditionally essential” nutrient.

Other names for Carnitine

L-carnitine

Where to find Carnitine

Carnitine is naturally synthesized in our bodies from the amino acids lysine and methionine. Most dairy products, as well as red meats, eggs, and chicken also contain this amino acid.

PERFORMANCE BENEFITS

Why athletes use Carnitine

Research has shown that a carnitine deficiency may result in lower ATP (muscle energy) levels. Given that carnitine turnover is accelerated during exercise, shortages could limit the amount of energy available to muscles. The result is a rapid onset of fatigue and subsequent compromised recovery.

Ways that Carnitine can enhance Fat Loss:
  • Increase fat metabolism by transferring fats into cells to be burned for energy
Ways that Carnitine can enhance Energy & Endurance:
  • Reduce muscle fatigue and soreness by preserving muscle glycogen stores
  • Support energy production through the use of fatty acids

HEALTH BENEFITS

Signs of Carnitine deficiency

No deficiency conditions are known to exist.

Potential uses for Carnitine

Research indicates that Carnitine may be useful in the treatment of:

  • Cardiovascular disease
  • Fatigue/Weakness
  • ALS
  • Obesity
  • Male infertility

DISCUSSION

More about Carnitine

Carnitine is classified as a nonessential amino acid because our bodies naturally synthesize it. It’s required for our hearts to function efficiently, especially during exercise. Carnitine’s also needed to transfer fatty acids across cell membranes into the mitochondria (the power factories of our cells) to be used as energy. And recently, research has revealed that individuals who supplement with carnitine while engaging in intense exercise programs are less likely to experience muscle soreness and fatigue than those who do not.

Support optimal fat use

Carnitine is responsible for transferring fatty acids across cell membranes to the mitochondria, which in turn uses the fat as a primary source of energy. Supplementing with carnitine may help ensure the fatty acids are burned (oxidized) as fuel. In fact, experts have suggested that carnitine does not increase the rate of weight loss but rather could increase the ratio of fat to muscle loss, thus preserving muscle mass while increasing the rate fat is burned. But if carnitine levels are not optimal in our bodies, the level of fats in our bloodstream may be high, which may actually interfere with our ability to lose bodyfat.

A key energy generator

Because the use of carnitine — called carnitine turnover — is accelerated during exercise, and the level of carnitine in our bodies partially determines the amount of energy produced within our muscles, supplementing with carnitine may allow our bodies to generate even greater amounts of energy. Remember, carnitine enhances the burning of fatty acids, which is believed to be used as an energy source during exercise. Carnitine may even increase the rate the liver uses fats, which is another potential energy-generating process.


Delay muscle fatigue

Some research suggests that carnitine could help reduce muscle fatigue and soreness by decreasing the amount of oxygen our muscle cells need during intense exercise sessions and preserving muscle glycogen stores. One study showed athletes, marathon runners in particular, lose large amounts of carnitine during prolonged exercise bouts, which may lead to slowed recovery and early onset of muscle fatigue and soreness.


A healthy heart

Research has also demonstrated that carnitine may reduce blood fats, namely triglycerides and cholesterol, as a result of optimal fat metabolism. Scientists have paired this with its effects on energy production in the heart and theorized it has heart-healthy effects.

In conclusion

Quite simply, carnitine is important for assisting the body with proper fat use, creating an optimal environment to increase capacity for prolonged and/or intense exercise sessions, and resisting muscle fatigue and post-workout soreness.

NOTES ON USAGE

Amount

For fat loss and increased energy during exercise, positive results have been reported with use of 2,000 to 4,000 mg, usually divided in 2 dosages throughout the day.

Theoretically, the higher the levels of carnitine in muscle, the better, as it may lead to more bodyfat being transported and burned.

For heart-healthy benefits, many nutritionists recommend 1,000 to 2,000 mg 2 times daily.

Timing

Carnitine should be supplemented about 30 minutes to 1 hour before exercise. Because other amino acids contained in proteins may hinder or compete for absorption, carnitine shouldn’t be used with protein foods or supplements.

Synergists of Carnitine

CoQ10 may improve carnitine’s heart healthy effects.

7-Keto may help improve the effects of non-stimulatory fat metabolism.

Safety of Carnitine

If you have liver or kidney disease or diabetes, carnitine is not recommended.

Toxicity of Carnitine

No known toxicity.

Bans and restrictions

None reported.

RELATED RESEARCH

  • Crayhon, R., The Carnitine Miracle: The Supernutrient Program That Promotes High Energy, Fat Burning, Heart Health, Brain Wellness, and Longevity (M Evans & Co, 1998).
  • Dragan, I.G., et al., “Studies Concerning Chronic and Acute Effects of L-Carnitina in Elite Athletes,” Physiologie 26.2 (1989) : 111-29.
  • Kuratsune, H., et al, “Acylcarnitine Deficiency in Chronic Fatigue Syndrome,” Clin Infect Dis 18.S1 (1994) : S62-7.
  • Pola, P., et al., “Carnitine in the Therapy of Dyslipidemic Patients,” Curr Ther Res Clin Exp 27.2 (1980) : 208-216.
  • Pola, P., et al., “Statistical Evaluation of Long-Term L-Carnitine Therapy in Hyper-Lipo Proteinemias,” Drugs Exp Clin Res 9.12 (1983) : 925-934.