There are a couple of little studies, like a British one in the 70s with 100 mg/day Dianabol, some Scandinavian one same time period with various athletes doing various things, and the Forbes study on dose/response curve that had ONE athlete using high dose (a gram per week) but basically there is very little and there never will be much.
This is because there is no way to do it as
solid science, since you will never get an independent review board to agree to your administering high dose anabolic steroids to subjects. Instead you can only do a gossip
magazine type of thing in which you depend on the athletes to tell you what they are doing (athletes lie!) and you will not have consistent data, but rather 20 guys doing 20 different things, and basically you won't have anything publishable, unless the editors
are looking for gossip.
Closest to this is the JAMA study on use of testosterone at 600 mg/week in normal men. That is only what I would call medium dose though and these were not athletes.