Acute L Carnitine Supplementation Does Not Improve CrossFit Performance: A Randomized, Double Blind, Placebo Controlled Crossover Study Should You Take Supplements On Rest Days? AS IT IS Nutrition Lets talk about L Carnitine, If youre in the gym community, youve probably heard of L Carnitine but what actually is it?, L Carnitine is a naturally occurring compound that plays a role in helping L Carnitine Supplements Nature's Best Liquid L Carnitine 1500, Blue Raspberry, 16 oz (473 ml)