L-Carnitine is a naturally occurring amino acidrequired for the oxidation and transport of fatty acids. Found mostly in the heart, skeletal muscle and brain, L-Carnitine is synthesized in the body, primarily liver and kidneys, from essential amino acids obtained through the diet. Population studies have shown that vegetarians are commonly unable to meet optimal carnitine needs. Improved lipid transport, may in turn, facilitate weight management, increase exercise performance and maintain healthy cholesterol levels already within a normal range.* L-Carnitine supplementation has also been claimed to decrease muscle fatigue by preserving muscle glycogen through the preferential use of fat as energy.* Theoretically, L-Carnitine could produce great results for decreasing weight and increasing exercise performance.*
Carnitine supplementation has been claimed to increase fatty acid oxidation and decrease muscle fatigue, therefore, preserving muscle glycogen by using fat as energy.* Theoretically, the more carnitine in the muscle or plasma the more transport of fatty acids to the mitochondria for oxidation.* Hence, oral carnitine supplementation may facilitate weight loss and increase exercise performance.*
Energy Usage:During aerobic exercise, skeletal muscle relies mostly on the breakdown of carbohydrates (CHO) and fats for energy. Once the level of exercise increases, so does the utilization of CHO versus fat. High intense training leads to a loss of glycogen (stored energy), which is known to restrict ones ability to maintain high intense exercise. Various nutritional interventions have been designed to overcome this inhibition. CHO loading as well as CHO intake during exercise are known to maintain a high rate of CHO utilization and to delay weariness from exertion. Enhancing fatty acid (FA) oxidation during exercise decreases glycogen breakdown, therefore, increasing aerobic capacity (1). Since carnitine is vital for the transport of fat into the cell for oxidation, the theory is, more available carnitine more fat breakdown.*
Conclusion: Although there is limited data showing the benefits of carnitine supplementation on exercise performance and weight loss, some athletes under certain conditions might see positive results.* In theory, L-Carnitine supplementation may aid in weight loss and increase exercise performance.*
References:
- Br J Nutr, 79:117, 1998.