My brother in law is forty-three and has a five twenty-five bench with no problems. His goal is to hit 600 by the end of the year, natural or not. He has not juiced in years but said he would to hit 600. Anyway. all he wanted me to get him was either one bottle of suspension, or some anadrol. I don't think that those strongman take juice on the same level as bodybuilders, or even some of us. A lot of them just have that incredible strenght that some of us will never experience
Actually, a guy who's going to be in the next World's Strongest Man works out at my gym. They had a camera crew in one day filming him. He asked me to spot him too for skullcrushers and I damn near let the weight fall on his head - camera crews are VERY distracting. Anyway, I listened to him tell them he won't touch steroids. He's also a lot leaner than most of those other competitors.
He wasn't nearly as large as most strongmen. His size is definitely achievable naturally, and judging from his strenght I'd say that was probably possible as well with th eproper genetics. I don'tt hink he'll win or even come close.
Some of those guys who do strongman just have developed crazy functional strength through hard manual labor. A few years back a self-described "redneck" who hardly lifted placed very high in the competition in the US that Jouko Ahola won. I saw an article and pics, and he really didn't look big at all.