Sorry guys, but I don't think the time on=time off theory is all that good. If you take sust for 8 weeks, its really in your system for another 3-4 weeks after your last shot. So if you only take 8 weeks off, you're really only taking close to 4 weeks off, which doesn't seem like enought time for natural test levels to return to normal. I guess it also depends if you believe in receptor downgrade or not though. Just my 2 cents.