I'd love to hear your sources about "all" the gymnasts who are on PEDs. I was a gymnast for 16 years, competed nationally for 10 years, personally knew and competed against some of the US team members in the 2008 and 2012 Olympics.

I have never, ever, heard even a whiff of anyone taking anything remotely on the wrong side of rules for "performance enhancing" substances.

Bodyweight workouts can be incredibly challenging and develop not just strength but explosive power. Regular pushups too easy? Try clapping pushups or handstand pushups or an iron cross to work your deltoids, pecs and triceps.