An Overview of the Dietary Ingredient Carnitine

Carnitine is a natural component of mammalian tissue and is involved in multiple physiological roles. In relation to physical exercise, these include, but are not limited to, providing antioxidant protection, increasing nitric oxide production and/or maintaining circulating nitric oxide, and working to enhance energy production (e.g., fatty acid oxidation). These outcomes may be directly or indirectly related to improved exercise performance or recovery from strenuous exercise. Some studies have noted favorable outcomes with regard to exercise performance or related measures following carnitine supplementation, whereas others have failed to demonstrate an ergogenic effect, in particular when carnitine is used by healthy, exercise-trained individuals. The type and dosage of carnitine used vary considerably across studies, and few direct comparisons have been made between carnitine forms. This chapter provides a brief overview of the work in the area of carnitine supplementation