It was kind of unclear to me at first. But the gist of it was that the teams of two Amazing Racers had to select from what the announcer said was the Ethiopian national running team and then run a four person relay race (against any other team present). When they finished they were handed their next clue from the national team coach.
But all they seemed to have to do is make one lap of the track. It was like a 4X400m race - only there was no real race to speak of, at least not the way they presented it. They just had to run and I guess if they ended up beating the other ARers, then they had that bit of time advantage. Only all the ARers started whenever they got to the stadium - which varied greatly.
They didn't announce who any of the Ethiopian runners were nor their credentials and there was no clock on anybody. There was some entertainment value in watching how slow some the ARers were (especially Kentra who seemed to bonk at 150 metres into the race, dying on her feet). Hayden seemed okay. She was the former track athlete who ran for Arizona, if I remember correctly. She actually said on camera that she had a lot of experience with the 4X400 event.