It must be understood though, that anytime fat cells are burned, the stored THC metabolites are released back into the bloodstream. From there, the kidneys filter the metabolites from the bloodstream and deposit them into the bladder.
For this reason, all fat-burning activities should be avoided if a person has 3 days or less before the U/A. During this period, youd want to eat large meals and be as lazy as possible to prevent a bunch of THC metabolites from being released into the bloodstream, which will end up in the urine to be detected.