Leading contenders in Chicago today
Mo Farah, aged 35 Great Britain PB: 2hr 6min 21sec
Easily the most accomplished man on the track, Farah is only the eighth fastest athlete in the field, although he was very impressive in London this year, finishing third, and is targeting the European record here.
Galen Rupp, 32, United States PB: 2-06-07
The American triumphed over an easier field to win this race last year and has shown the marathon suits him better than the track. His build-up has been hampered by an Achilles issue.
Geoffrey Kirui, 25, Kenya PB: 2-06-27
Younger than most of his rivals, Kirui won the world title last year and also claimed victory in Boston. His personal best is not that quick, but his potential means he is many people’s favourite.
Mosinet Geremew, 26, Ethiopia PB: 2-04-00
Geremew is the fastest man in the field after winning a super-quick Dubai Marathon in January. He has excelled over the halfmarathon distance.
Birhanu Legese, 24 Ethiopia PB: 2-04-15
The youngest athlete in the elite field, Legese produced the third-fastest debut marathon in history in Dubai this year behind Geremew. This is only his second marathon.