More than you would think, as I've read. But many opt for the lesser route of HRT in the later years for simple hormonal maintenance, which many of us qualify for without having ever done steroids. (me, for one)
Also, there is a large difference between the contestants and heavy users compared to those who used them more supplementally. The more dosage utilized, the greater the side effects are, and there are many out there who still use after many years safely, by limiting (yes Virginia, you can control) themselves to lower dosages. And OTOH, there are those who go nuts at the first signs of improvement and think "more is better".