Gymnastics is one of my favorite sports to watch, because the athletes do things that I believe are simply not possible for human beings to actually accomplish. If I were a conspiracy nut, I would definitely have come up with some explanation for how they fooled me into thinking they actually did what I saw.
So, given the amazing feats that these gymnasts perform, I was moderately underwhelmed by the video - until I realized I had never seen anyone do that BETWEEN two horizontal bars. So now, I'm impressed. Check it out. I promise it's no optical illusion.