Four-time Olympic gold medalist, Sir Mo Farah from Britain has decided to defend his championship of the Chicago Marathon by attending the event again on October 13. This decision meant that he will not participate in the 2019 IAAF World Athletics Championships in Doha, Qatar, on behalf of his country.

"I am returning to the Chicago Marathon on 13 Oct. Winning there last year and breaking the European record was special. Having discussed with my team and to ensure I have the best chance of achieving this goal, my focus for 2019 will be solely on the roads," wrote Farah on Twitter.

On October 7, 2018, Farah won the title at the Chicago Marathon at 2:05:11, which is his personal best, the national record in Britain and the best record in Europe. It was also the first World Marathon Major he had won.

It's safe to say that Farah is the most successful British track athlete in modern Olympics after he won both men's 5,000-meter and men's 10,000-meter race at the 2012 and 2016 Summer Olympics. He is also the second athlete, after Lasse Virén of Finland, who won both men's 5,000m and men's 10,000m golds at two consecutive modern Olympics.

Though Farah won the title of men's 10,000m event at the 2017 IAAF World Athletics Championships in London, UK, he decided to switch to marathon after that. Moreover, this year's Chicago Marathon will be only seven days after men's 10,000m final of the World Championships, too short for Farah to rest and adapt himself to time differences, making it even harder for him to go to Doha.

Besides Farah, the 2019 Chicago Marathon will also welcome two other heavyweight runners, Galen Rupp and Jordan Hasay.

This will be the third time for Rupp to run the Chicago Marathon after he won it in 2017 and came in fifth in 2018. Though he had Achilles tendon surgery last year, Rupp is back in full health. "I have been pouring all of my energy into my recovery and returning strong in 2019. I look forward to being at my best again," said Rupp.

Hasay finished the 2017 Chicago Marathon as No.3 at 2:20:57, which was the second-best record of all American female marathon athletes. However, Hasay suffered a stress fracture in her heel and thus almost missed the whole 2018 season. Fortunately, she managed to recover and come back in the 2019 Boston Marathon which she finished at 2:25:20. After Boston, Hasay announced that she aimed to tie the American record of 2:19:36 in the Chicago Marathon.