I know current college guys that do it and it is quite obvious. What do you think redshirt years do? They get told when they will be tested. It's not that hard to do it. I have seen so many guys bulking up rapidly in the off seasons and there is no way they do it that quickly and stay cut otherwise.
Seriously based on your statement alone you are a complete and utter DUMBASS.
I have played at WVA 88-91 and was a grad asst at U Alabama in 92-93'
We were NEVER given advanced notice to drug testing.
You are Wrong again... THEY CAN do it that quickly, at ages 18-22 the human natural test level is sky high, and on top of that there are ELITE genetically gifted athletes, not your typical Div III or H.S. athlete.
When you have access to a training table where you are fed all the steak/chicken/pasta/potatos you can eat, then you have a team of 4-6 strength coaches in the weight room pushing you through each workout IT IS CERTAINLY possible to make very FAST , EXTREME GAINS.
Just take another look at the intensity of the "atmosphere" in the weight room.