I want to be clear: I am NOT suggesting that if you have a drug test in a week you can drink 8 glasses of water a day and expect any significant changes in your metabolism. What I am saying is that over a long period of time - a few months - there are things you can do in addition to daily vigorous exercise that will cause your body to burn fat faster, and thus eliminate THC faster.
What needs to be realized is that not many people are fortunate to have a few months notice of an upcoming drug test.