Good fighters who arent taking anyything illegal just dont stay so ripped!

Look at Duran as he moved up or any other fighter in history, they always lose something. Well not really lose, just that as a powerfull puncher moves up in weight, his muscles mass hasnt really changed and so his punches havent really got any more powerfull. Sometimes the fighter can be more relaxed because they havent had to drain down to weight and there punches can be stronger but Manny has kept everything. Speed, strength but the most dubious thing about his move up in weight is his body composition! Ask any bodybuilder how hard it is to grow muscle naturally, let alone an athlete that has to balance size and speed!