But the Kenyans hope that tackling an unfamiliar flat, looped course at the 2020 London Marathon on Sunday (October 4) could play in their favour with 'personal bests'.
“A world record is possible.” - Brigid Kosgei on 2020 London Marathon
Kosgei broke Paula Radcliffe's long standing record in October 2019 with a time of 2 hours 14 minutes 4 seconds.
Cheruiyot was denied back-to-back wins in London last year by Kosgei.
Both women are keen to show their best form in the park and gardens near the iconic Buckingham Palace.
“According to the race organisers, the first half will be 68.15 to 68:30 minutes, that’s a 2:16 [finish], which is quick,” said Cheruiyot.
2020 London Marathon: A looped course
Both Cheruiyot and Kosgei are relative newcomers to the marathon.
Kosgei ran her first marathon in 2015, while Cheruiyot switched fully to the road a year after her 5,000m gold at Rio 2016.
“I have never run on a looped course, so I really don’t know what to expect,” said Kosgei.
“For marathon to go loops, [as in] loops all the way, it could be difficult,” Cheruiyot added.
“The circuit will depend on the way you will run it. It’s not normal for everyone.
"Some people say that sometimes it can favour somebody who used to run track and field. I can say yes.”
“I want to always shine and improve my personal best,” said Brigid Kosgie who, at 26, became the youngest woman to win a London Marathon last year.
"A world record is possible if the weather holds and the rest of the field is in the top [form]."
The forecast is for a cloudy day with a slight chance of rain.
Cheruiyot, the 2018 London Marathon champion, feels the unknown course could lead her to good fortunes in her fourth attempt in the British capital.
“If the weather will be good on Sunday, I think I will run my personal best, because the last two-and-a-half months, my training has been going on well,” the four-time Olympic medallist said.
“On Sunday it could be a bit cold as our race will start at 7:15am UK time and it’s slightly cold then.
"For me as long as there is no wind, it can drizzle a little bit but that can’t make me not to run [well],” Cheruiyot continued.
The 2018 win also saw her clock her personal best time of 2:18:31.
"I feel comfortable as I have been running London since 2017 and I have been running for 22 years [so] I have confidence to do my best on Sunday."
Youth and experience
The two runners hail from the county of Elgeyo Marakwet in Kenya - a region famed for producing some of Kenya’s best runners.
Kosgei is feeling the pressure - the field also includes reigning marathon world champion Ruth Chepngetich.
“Ahead of a big race pressure is normal, because [there are] many top competitors and we fear each other.
"But Sunday will determine the real winner and who’s training pays off,” she said.
Kosgei is the only one of the top-ranked Kenyan trio who had a chance to race this season.
She was second at the Ras Al Khaimah Half Marathon in the UAE in February before her unsuccessful major track debut at the Diamond League in Brussels.
She finished behind Sifan Hassan when the Dutchwoman broke the world record for the most distance covered in one-hour but was disqualified for stepping out of the track.
“I didn’t know if you step on the line you will be disqualified. I was just in Brussels for the speed.”
Cheruiyot, 37, will be using the London Marathon as part of her preparations for what she hopes will be a career-changing 2021 season.
“I will run with my determination and strength. I will run with my calculations and that should carry me through to the finishing line,” said the four-time world champion considered one of Kenya’s most successful distance track runners.
What is still missing is [another] Olympic gold medal - Vivian Cheruiyot on Tokyo Olympics.
"I have the 5000m [gold] that I got in Rio. I still need one more. Probably next year if I’ll be given a chance to represent my country [in Tokyo] that is the time that I want to get that medal.”