They have raced all around the world and among the runners to beat at Sunday's Standard Chartered Marathon Singapore.

But speaking at Friday's pre-race press conference, race headliners Sharon Cherop, Beatrice Torotich, both Kenyans, and Bahraini Bah Aadam Ismaeel Khamis admitted that they are unlikely to clock anywhere close to their best times, on account of the Singapore heat and humidity.

The trio will be among 54,000 runners who will take to the streets on Sunday morning, over five different categories.

Click on the image below to view an interactive graphic showing the routes for the marathon.

"There will be a big difference because of the weather," said Cherop, who clocked her personal best time of 2hr 22min 28sec to finish second at September's Berlin Marathon.

Khamis, who boasts a personal best of 2:07, added: "The weather here is very hot. For me, 2:15 may be possible; 2:07 is not."