Andre Penner/Associated Press

Vitor Belfort is red-hot. And when I say red-hot, I mean sizzling as if he was re-entering earth's atmosphere.

His juggernaut performances of 2013 included scintillating knockouts of middleweight top contenders Michael Bisping and Luke Rockhold, as well as becoming the first fighter to ever knock out Dan Henderson.

With such success, "The Phenom" has once again reclaimed his spot atop the division and will soon challenge UFC champion Chris Weidman later this year for Octagon supremacy.

Remember, Belfort's last title shot featured him getting kicked in the face by Anderson Silva, a legendary fighter who Weidman beat twice last year.

Despite all of his resurgent promise and overall excellence as a physically freakish 36-year-old, the Brazilian can't shake the critics when it comes to his storied testosterone replacement therapy usage.

The re-energized veteran recently posted an image on Instagram, thanking his fans for their support since he began his career:

Now while Belfort's post was in good spirits, it once again opens up the floor for TRT debates.

How is it ethically and physically smart for a 36-year-old to look like his former 19-year-old self? When is exempted TRT usage too much in a sport fueled by youth?

It's an eye-opening image, especially for anyone unaware of how dependent aging fighters like Belfort are on increasing their declining testosterone levels.

In any case, Belfort needs to maintain his ferocity when he meets Weidman for the middleweight championship sometime in 2014. Whether or not he'll be able to get the nod from the Nevada State Athletic Commission regarding TRT usage for that looming battle has yet to be determined.

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