i think that prison sh#@ is a myth....people were probabley big before they went in anyways...plus that food is jacked w/ cals cause they try to feed them what they need in three meals.....and u can get roids, and suplements in prison.....so if u eat the protein and do a good body weight program it is possible to gain size. So say u are in prison, get the sups, have a gym or not, what else do they have to focus on...pretty much nothing, just sit on ur ass in a cell and rest ur body till ur next workout