Legitimate Testosterone Replacement Therapy restores the serum testosterone levels of a patient to so-called "optimal" levels, usually somewhere between 500-1000ng/dl. The issue with TRT in professional sports isn't that dosage, I mean, that's an ethical concern, of course, but those serum levels offer very little "advantage," since they are widely considered to be that of an average man, let alone a professional athlete. The actual advantage to being on TRT is that traditional sport drug testing relies a lot on the T:E test, as an indicator of the likelihood that an athlete is using synthetic testosterone. Guys are often caught with "elevated T:E ratios," and so it's pretty obvious they were using synthetic testosterone in their training camps. With an athlete on TRT, an indicator of Testosterone abuse is immediately removed from the testing panel. An athlete can then safely use higher doses throughout the camp, knowing that as long as the serum level is low at testing time, he can go unpunished.
If you're on TRT and not being tested randomly throughout the camp, you can take advantage of short-ester testosterone. I could have 10x more serum testosterone than your average male, but by using short-chain esters or testosterone suspension, in a matter of hours my Serum levels will be down to "low", and therefore I'll pass the secondary testing.
So long story short, unless you randomly test an athlete on TRT, guys like Vitor could just use superhuman doses throughout training, and, in theory, perhaps even during the fight (though that would offer little benefit), and testers would be none the wiser.