gh15 is on the ropes so has to use the qualifier about 6% bodyfat. If I could naturally get 19 inch arms and be in the same condition that I was when I won Mr Canada in 1970 then I win the argument.
I have absolutely no desire to get as lean as the pros do where you see striations in their glutes. I would use extreme training methods and special equipment to achieve my size.
Guys like Bud Counts and Leroy Colbert had honest 19 inch arms in the old days before steroids ruined bodybuilding.