Should You Take Supplements On Rest Days? AS IT IS Nutrition Liquid L Carnitine 1500, Blue Raspberry, 16 oz (473 ml) L Carnitine Tartrate Supplementation for 5 Weeks Improves Exercise Recovery in Men and Women: A Randomized, Double Blind, Placebo Controlled Trial L Carnitine is not a magic fat burner It won't melt fat, build muscle, or replace hard work. The only thing it burns is your money Stick to the basics