Former HM world record holder Kibiwott Kandie and Kenenisa Bekele also running, while Almaz Ayana and 2019 Boston champ Worknesh Degefa lead the women.
Joshua Cheptegei is running 140 to 160 kilometers a week in preparation for his marathon debut in Valencia on December 3, through relentless mud in Uganda.
Cheptegei has been running 85 to 100 miles a week getting ready for his debut, but says he's "not actually looking to run fast the first time. He said, "For me, I want to learn. The best for me is to see myself being on the podium, whether I run 2:03 or 2:04. I don't know what will take me to the podium. For me what is important is to enjoy the race and see what happens after 35 kilometers."