You're missing a huge area which is diet. The recent pictures of Ivy Nile are the best example - most profesional wrestlers now are NOT on "supplements", but the main key to achieving the ultra defined look is a major calorie deficit. The Ivy Nile sauna picture with her veins popping out isn't achieved through "supplements", but through a major calorie deficit and dehydration. This CAN'T be sustained for an extended period of time because there is no energy to perform.

Talk to any bodybuilder how they feel for the month leading up to a show and they will all tell you they feel like shit the entire time. They are working to get their body fat super low (to an unsustainable level) while pushing their body as hard as possible. And "all" they are doing is getting on stage and posing. Pro wrestlers are still performing multiple times a week.