1. One of the main rules of race walking is that competitors must keep at least one foot on the ground at all time.
2. And the front leg must always be straight.
3. The sport's characteristic hip movement is necessary so that the athlete avoids bending the knee.
4. Violations of the above rules are punished by the judges with a red card. If the athlete receives three of them, they are eliminated from the race.
5. Because the events are so difficult to monitor, the sport is very subjective, and complaints to the judges are extremely common. (A little bit like soccer.)
6. At the 2000 Olympic Games in Sydney, Australian athlete Jane Saville was about to win the gold when she was disqualified for excessive infractions. A reporter asked her if she wanted anything. "A gun to shoot myself," she replied.
7. The sport dates back to an amateur practice that emerged in England during the 19th century called "pedestrianism," which was essentially just competitive walking.
8. According to an 1876 issue of The New York Times, two practitioners of pedestrianism trekked 1,000 miles in 1,000 hours in one particularly heated race.
9. Race walking debuted at the 1904 Olympics as one of the ten sports of the decathlon. At the following summer Olympics in1908, it was formalized as an independent sport.
10. At the Olympics, men compete in both 20km and 50km races. Women only compete in a 20km event.
11. The women's competition didn't debut until the 1992 Olympics in Barcelona.
12. The sport was brought to Brazil in 1937 by José Carlos Daudt and Tulio de Rose, who had learned about race walking in the previous year's Games in Berlin. Brazil has six athletes competing across all three events at the Rio games this year.
13. But Brazil still doesn't have any Olympic medals in race walking.
14. America has only taken home two medals in the event, both of them bronze. They were both won by Larry Young at the 1968 and 1972 games.
15. Athletes from the now defunct Soviet Union have won the most race walking events at the Olympics, with a whopping 13 medals.