It felt like shooting inside of a club.  A sweaty, hot, and full of action night club. 

This was a very cool shoot! Super entertaining, and there's action everywhere. Photos above were taken with the Sigma F1.4 85mm lens.  

Of  course you could use a lens that can go higher ( like a 105 or 70-200 ) wouldn't hurt. The 85 in this scenario worked best I think because of how much you can crop. So like if I take a picture of a person, I can zoom really-  really far in on their face with limited black and white noise. It's great! because you stand there outside of the ring, snap all these sick shots, and apply the denoise button to smoothen things out. 

Another thing to take note is that these people are very fast. This is a sport don't forget ( I think ), so quick shutters would help get those clean shots. For fast  moving subjects, I like to set my shutter speed to anywhere around "1/320" or higher. I was pretty close to these guys so I kept the aperture low and just walked around the ring.