I just stumbled into this old discussion. It's excellent. Sad to see more people didn't contribute. I've always enjoyed watching "transformation" videos or photo sets to try to figure out when someone really started using. There are a lot of such videos, for example on YouTube. And some Tumblr sites used to have them too. For a look at exceptional but largely natural physiques take a look at gymnasts, such as Simone Biles, and sprinters (100, 200, and 40 yard or meter distance). Pole vaulters would be another group. While I know there is some drug use even here, especially in track and field, it's likely that many well-built competitors are natural.