slipping past the blood and urine tests?

What can you use that can be expelled from the body in a short period and never ever show up in a blood or urine test? For sports that test athletes religiously what can you use to add strength and power that you can cycle off of for an upcoming event to pass a test and immediatelty get back on after competition. Is it pointless to start a cycle if in 4 weeks or 8 weeks i'll have to pass a piss test? No if ands or buts about passing the test. It has to be my urine or my blood. Since hgh and test naturally occur in the body can you take this and it never show up as being synthetically injected? Is it a waste of $$ to just take one of these or the other. What's the minimum time you should cycle those. Are there any other's that would work the same way?