Depends on what era we’re considering old school, but a lot of guys ran a deca or primo base (depending on if they were in the US or Europe for the most part). That plus winstrol and halo, strict dieting sometimes with no carbs, and a lot of them changed up their training to extremely high volume sometimes twice a day for hours plus cardio
Also, we really only see the genetic elite because their photos have lasted through time, versus today where literally everyone who lifts has an IG. The guys who were fatter and dealing with high estro and gyno didn’t place well, and there’s few pics of these guys
Just a few things I’ve gathered throughout the years, but I never lived in the old school era so take all this with a grain of salt