Essential for the production of energy and for the metabolism of lipids, l-carnitine is an amino acid that is one of the basic components of the daily diet. Its main role is to transport fatty acids into cellular mitochondria, where they are burned thanks to the beta-oxidation process. L-Carnitine transports fatty acids within the mitochondria. These power plants that are located inside the cells provide the latter with energy by metabolizing fatty acids. Numerous recent studies have shown the better bio-availability of L-carnitine fumarate compared to that of L-carnitine tartrate, usually proposed to improve sports performance. In fact, L-carnitine fumarate allows to release, in proportion, a greater quantity of active ingredients, with a more constant and more homogeneous progression over time.