Carnitine, also known as L-carnitine, is an amino acid derivative that plays a critical role in the metabolism of lipids and energy production. It facilitates the transport of long-chain fatty acids into the mitochondria where they are oxidized to produce ATP (adenosine triphosphate), thereby supporting cellular energy levels. Carnitine supplements are widely used in sports nutrition due to their potential to enhance endurance performance and reduce fatigue. Research suggests that carnitine can help improve exercise tolerance, particularly during high-intensity workouts, by improving the efficiency of fat metabolism. Additionally, it has been studied for its role in cardiovascular health, liver function, and cognitive function, although more research is needed to fully understand these potential benefits.