It would be nice to have another Olympic medal - Mo FarahLondon Marathon 2019Date: Sunday, 28 April Start times: Wheelchair races 09:05 BST, ambulatory races 09:15, women's race 09:25 and men's race and masses 10:10Coverage: Follow live on BBC One, BBC Two, BBC iPlayer, BBC Radio 5 Live Sports Extra, BBC Red Button and online. Full details.
Four-time Olympic champion Mo Farah says it would be an "amazing achievement" to topple Eliud Kipchoge at Sunday's London Marathon.
Kenyan Kipchoge set the world record of two hours one minute 39 seconds in Berlin in September - three and a half minutes faster than Farah's best - and has three of the top 10 marathon times.
"Eliud is a great athlete and the world record holder," said the Briton, 36.
"I'm going to go out there and give it my best."
Farah's final preparations for the race have coincided with an extraordinary row with Ethiopian long-distance great Haile Gebrselassie.
Farah alleged that he had thousands of pounds stolen while staying at a hotel owned by Gebrselassie, who responded by revealing that Farah was involved in a physical fight with another guest.
He also said that the two's relationship deteriorated after he barred Farah from bringing Jama Aden, a coach who was arrested as part of an anti-doping operation in Spain in 2016, to the hotel.
Farah denies the latter claim.
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Kipchoge, 34, won the London Marathon for a third time (previous wins 2015 and 2016) last year, while Farah finished third, setting a new British record on his debut over the distance.
Since switching from track in 2013, Kipchoge has won all but one of his 11 marathons including Olympic gold at Rio 2016. He came within 26 seconds of breaking the two-hour barrier at an unofficial assisted race in the Italian city of Monza in May 2017.
By contrast, Farah's best - a 2:05:11 effort in victory in Chicago in October - is only 90th in the all-time list.
"Racing against Eliud in London was learning the hard way - but I believe I learned a lot," Farah said of last year's race.
"After each race you get a bit better, that bit more experienced. I believe I could have gone a little bit faster in Chicago - 2:04-something, but I don't know.
"It's nice to be back in my home city; it's really exciting. I feel more nervous and hungry again. I'm not used to winning in the marathon, so I feel like I've got my mojo back."
Mo Farah: How the four-time Olympic champion is preparing for the London Marathon
Kipchoge says the prospect of a shock Farah victory helps push him to produce his best.
"Anybody can be beaten - Mo can beat me, others can beat me, but the best thing is that if you can accept the results, that's the only way to enjoy the sport," he said.
"I'm really surprised that Mo is learning so fast. It doesn't worry me, but it makes me get interested in him because that's what you want in sport; it's what helps you perform."
Mo Farah and Eliud Kipchoge's duel divides north London with the former a big Arsenal fan and the latter a Tottenham supporter
Scotland's Callum Hawkins, 26, makes his return to the marathon for the first time since collapsing from exhaustion while leading the Commonwealth Games marathon on Australia's Gold Coast last year.
He has previously claimed a ninth-place finish at Rio 2016 and was fourth in the World Championships in London the following summer.
Hawkins receives treatment after collapsing at the Commonwealth Games in 2018
"It would also be nice to get that monkey off my back by showing I can run in the heat," Hawkins said, although the forecast for London on Sunday is currently 14 degrees and cloudy.
"Normally, in hot races, I've been fine but it was just an accumulation of things in the Gold Coast. I got a bad bug bite the week before and ended up on anti-inflammatories, which knocked my system off a little bit. Maybe I was hot-headed, too, going from a long way out and not taking my foot off the gas."
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Last year's winner Vivian Cheruiyot and three-time winner Mary Keitany - both Kenyan - will go head-to-head in a repeat of last year's dramatic women's race.
Keitany, 37, already in possession of the women-only mark, ran with male pacemakers last year in an attempt to overhaul Paula Radcliffe's 15-year-old mixed race world record.
However, she slowed in the second half of the race, allowing fellow Kenyan Cheruiyot, now 35, to surge through to victory.
"In marathons there are many challenges. If you fail today, make sure you learn something so you do not repeat the same mistake," said Keitany.
Cheruiyot finished fourth on her London Marathon debut in 2017 before winning in 2018
"It was not nice to lose like that last year but in the marathon, you have to learn from your mistakes."
Britain's Lily Partridge, 28, is back in the field after her eighth-place finish in 2018, with 27-year-old compatriot Charlotte Perdue, who was a second faster when finishing 15th in 2017, alongside her.
Weir aims for ninth London Marathon titleMarcel Hug, David Weir and Dan Romanchuk are the main contenders for the men's wheelchair title
British Paralympic great David Weir will aim for a ninth wheelchair title as he competes for the 20th time in his home town.
The 39-year-old retired from track racing in 2017 and says he is relishing concentrating on the road as he closes in on Tokyo 2020.
"I'm just focused on the marathon now, and going to Tokyo," he said.
"I don't miss the track at all, and I enjoy marathon training. I'm happy doing just one event and I'm getting summers off, socialising and seeing my kids more."
Weir finished fifth on his London Marathon debut in 2000 and has since come home first in 2002, 2006, 2007, 2008, 2011, 2012, 2017 and 2018.
One of his chief threats this year is Dan Romanchuk. The 20-year-old American beat both Weir and Swiss rival Marcel Hug, 33, to win the Chicago and New York titles last year. Hug took the London title in 2014 and 2016.
"I'll have a race plan for Sunday but if Dan goes off quickly we'll have to go with him," said Weir.
"It depends what happens on the day. The pack's often there at the end in London. We'll see."
Australian Madison de Rozario, 25, will defend her women's title against in-form Swiss Manuela Schar. Schar, 34, is the current holder of the Berlin, Chicago, New York, Tokyo and Boston titles. Adding London to her collection would complete a clean sweep of the major world marathons.
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While Farah and Kipchoge fight it out at the sharp end, around 40,000 others will be pounding the streets of London behind them.
"This weekend we will reach one billion pounds raised for charity by runners, with more than half of that coming in the last nine years," said race director Hugh Brasher.
In the first race in 1981, co-founded by his father and former Olympic gold medallist Chris Brasher, 5% of finishers were female, while this year that figure is expected to be around 45%.
Eleven ever-presents - those who have run every year since the first London Marathon in 1981 - will also take part, including 85-year-old Kenneth Jones, the oldest runner in the event.
Celebrities competing this year include former tennis player Amelie Mauresmo, EastEnders star Natalie Cassidy, TV presenter Helen Skelton, 2016 Great British Bake Off winner Candice Brown and broadcaster Chris Evans.
For advice on how to take up running and details of clubs near you, go to BBC Sport's Get Inspired website.