L-Carnitine is primarily involved with transporting long-chain fatty acids from the cell cytosol into the mitochondria. Since long chain fatty acids are oxidized (burned) in the mitochondria, L- Carnitine facilitates production of energy from fat. Oxidation (combining with oxygen) of the BCAAs is facilitated by L- Carnitine, providing a link between protein catabolism and cellular energy. Skeletal muscle contains 90% of total body carnitine in humans. L-Carnitine's Function during Aerobic Exercise: Helps Increase Fat Metabolism Increases Endurance Improves Definition Increases Utilization of Fatty Acids as Energy Decreases Lactate Build Up May Help in the Reduction of Ketones in the Blood. (important for diabetics)