Carnitine is a quaternary ammonium compound biosynthesized from the amino acids lysine and methionine. In living cells, it is required for the transport of fatty acids from the cytosol (intracellular fluid) into the mitochondria during the breakdown of lipids (fats) for the generation of metabolic energy. ( In laymen terms, it grabs the fats and carries them into the stove for fuel ) Carnitine exists in two stereoisomers: it’s biologically active form L-carnitine, ( the one we’re talking about) and the biologically inactive D-carnitine.
While most studies regarding the performance enhancing properties of L-carnitine have been centered around its role in mitochondrial β-oxidation, whereas supplementing with L-carnitine aided in fat burning. New studies however, have investigated another mechanism by which supplementing with L-carnitine could positively impact exercise recovery. Through cardiovascular research, it has been found that L-carnitine also enhances endothelial function. (The endothelium is the thin layer of cells that lines the interior surface of blood vessels, forming an interface between circulating blood in the lumen and the rest of the vessel wall. The endothelium has many important functions such as vasoconstriction and dilation, blood clotting, and acts as a filter.) The hypothesis that L-carnitine supplementation may aide in exercise recovery is centered on improving blood flow to muscle tissues and decreasing hypoxic stress and its resulting sequelae (consequences). These studies have shown a decrease in markers of purine catabolism ( a byproduct of which is uric acid), free radical generation and muscle soreness as a result of L-carnitine supplementation. Subsequently, after direct assessment of muscle tissue damage via magnetic resonance imaging, it has been shown that L-carnitine does have the ability to reduce tissue damage related to hypoxic stress.