L Carnitine benefits L Carnitine Benefits, Uses, Dosage, Foods, Side Effects Dr. Axe 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 Acetyl L Carnitine Functions & Benefits Bulk Nutrients Benefits of L Carnitine (especially for fitness enthusiasts): Fat Metabolism Helps transport fatty acids into the mitochondria to be burned for energy. Improved Exercise Performance May enhance stamina and reduce fatigue.