Men's 50k walk is about to start - no spoilers please. This will be the last time this event takes place at the Olympics. In Rio 2016, over 30 of the 80 participants did not finish (typical numbers), and many of those who finished or dropped out needed immediate medical attention. The early race leader in 2016, Yohann Diniz, opened a huge solo gap early and was lapping stragglers by 15k, but then stopped at a water station for over a minute. The following pack caught him shortly thereafter when fell over backwards on the street, requiring medical attention. He resumed walking a minute later, but stopped several more times and ended up finishing 8th. There is typically over a one hour gap between the race winner and the last finisher in the 50k. There will be excrement on the track and vomitting during and after the race. There are no US competitors in the 50k. There is no women's 50k walk. I think its the most brutal event at the summer Olympics. GL to all the heroic competitors in this epic race today.
edit - meant to specify, Diniz is the current world record holder, but is not competing this year.