I exercise every day and it took me over 3 weeks to burn off the THC from smoking every day-ish.
Exercise burns fat cells, but not the THC metabolites that were stored in the fat cells. THC is eliminated via excretion. When fat cells burn, the THC metabolites are released back into the bloodstream. The kidneys filter the THC metabolites from the bloodstream and deposits them into the bladder for the eventual exit. This is the main reason why THC carries a longer detection period than other types of drugs.

It is also the reason why exercise should be avoided if a person is failing home tests and his/her scheduled U/A is 3 days (or less) away. That way s/he wont be releasing a bunch of THC metabolites into the bloodstream, which will end up in the urine to be detected.