Mustafa Mohammad
Quite possibly one of the most dramatic transformations on our list belongs to Mustafa Mohammad of Jordan. Starting his career as a professional bodybuilder in 1989 with an eleventh place finish at the World Amateur Bodybuilding Championships, Mohammad was known for his incredible thigh development measuring in at over 32 inches. Despite this, however, he never reached the peak of his career as a result of such stiff competition although he managed a first place finish in the 1991 NABBA Mr. Universe competition in the Medium-Tall division.
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After winning two world titles in 1992 at only 26 years old, Mohammad did the unthinkable and retired for a little over nine years before returning in 2001 in what proved to be a disappointing end to his career. Never placing higher than third and ending his run with a ninth place finish at the 2006 Grand Prix Austria, it only took two years before the lack of steroids kicked in and left the former muscle-clad Jordanian looking like every other 40-year-old at the gym.