Carnitine Deficiency: What Is It, Causes, Symptoms, and More Osmosis Feeling low on energy or hitting a plateau in your fitness goals? L Carnitine can help your body convert fat into fuel, supporting higher energy levels, improved endurance, and a faster metabolism. L Carnitine Linus Pauling Institute Oregon State University Acetyl L Carnitine is more thought of as a fat burner. It's actually powerful tool for athletes looking to improve endurance, energy, and mental performance. Here's how you can integrate it into your routine for