Facebook founder Mark Zuckerberg is showing off his transformed physique as a result of his intense jiu jitsu and MMA training with UFC champions ahead of his potential bout with Elon Musk. 

TMZ reports that Zuckerberg spent a few days training with UFC middleweight champion Israel Adesanya and UFC featherweight champion Alexander Volkanovski who joined Zuckerberg at his Northern California residence following Saturday night's UFC 290 showcase in Vegas.

On Tuesday, Israel Adesanya shared a photo of the post-training session alongside Zuckerberg and Volkanovski. Izzy captioned the picture, "No fugazi with Mark," adding, "This is Serious Business!!"

Zuck later commented on the photo calling it "an honor" to train with the champs.