Learn Fat Burner vs Pre Workout Differences and Selection Guide Liquid L Carnitine supports fat metabolism and energy production by helping your body turn stored fat into usable fuel. Fast absorbing, stimulant free, and zero sugar or calories, it's a great pre workout option to boost L Carnitine as Pre Workout Supplement: Guide The Science of Good Health L Carnitine Does anyone recommend any good pre workout L carnitine liquid supplements that gives you a massive pump during workouts and a good energy boost Oxyenergys L Carnitine. My go to pre post workout supplement. Pre workout I usually take it before my workout session for energy production. Post workout Ill take it the day after my workout