There is no pressure. They have already entered the competition and thus have nothing to lose. What is worst, entering competition and giving a valiant effort, or entering the competition and showing you didnt belong in the first place. The competition does cause the release of adrenaline and other stress hormones, helping participants to perform on high level. There is no shame in putting forth a huge effort in this endeavor, where as, not trying will cause a lot of negative ideas about you. Trading is significantly different for reasons that are obvious.
I'm not sure you watched the video, and obviously many athletes competing feel quite a bit of pressure. Interesting to hear about the chemical differences between those who perform well and those who tend to crash in competitive environment.
I don't need to watch the video. The fact of the matter is, what athletes do is ultimately not that important and they often times are put on a pedestal they do not belong on. They are one more group of people who pat themselves on the back on a regular basis.