Mostly anecdotal, like most studies lol. But when I was doing my post-graduate research we tested specifically the Soleus and gastrocnemius muscles in rats. The rats performed typical ADL’s. One group of rats were on massive amounts of test, this group of rats saw an increase in the size and strength of those two muscles, while of course the control group did not. This of course does not take lots of things into account, but if you give someone steroids and change nothing else about their life (if they train continue to train, if they don’t continue to not) gains will be had.