Belfort is performing the best of his life, but is still adamant that is TRT regime just keeps him at a normal level:

"My (testosterone) levels were low in my last fight," Belfort told during a media scrum in his gym in Rio de Janeiro, Brazil. "I have all the exams to prove that I have a disease. Itís simple."

Brazilian MMA Athletic Commissionís medical director Dr. Marcio Tannure explained to that one of Belfort's pre-fight tests were below the normal limits, but that's "legal."

"Chael Sonnen has a license to fight in Vegas, and Iím doing everything by the book," Belfort said. "I have all the exams to prove it."