Back in his day, Eddie Robinson had some of the largest arms in bodybuilding. Verified at over 20". But Marko Savolainen came along and blew Eddie, and everyone else away. Check out this comparison side-by-side of each man doing a back double bi. Marko's arms exceeded 24" at one time and Gold Gym's Ed Connor measured Marko's arms, in contest shape at
23-5/8".