Steve Cram
BBC athletics commentator on BBC One

"The women are gathering themselves for a finish here. This is not about a time, it is about winning the London Marathon."

As the men's race just continues to defy belief with its ferocity and pace, the women are slowing up big time, it's a chess match now. Mare Dibaba at the front in purple, Tigist Tufa second and in good shape. Tactics, tactics, tactics.

At this stage, each of them are thinking of weaknesses in the other. "Does she have a good sprint kick? Can I run the finish out of her?"

Steve Cram
BBC athletics commentator on BBC One

"That was the fastest ever first half of a London Marathon."

So I can tell you that in crossing Tower Bridge the men hit the 20km mark at a pace that would break the world record if they stick at it. Remarkable.

On they go to the halfway point, will they slow? Not a chance. At halfway this group of half a dozen clock one hour, one minute and 24 seconds. That translates to a possible 2:02.48. The world record is 2:02:57. 

Wow, wow, wow.

Image source, .

The leading eight men approach Tower Bridge. It amazes me that even at this beefy pace they can talk to one another if needed.

Just look at Tower Bridge, lined with people, that'll make you pick those knees up.

Jonathan Edwards
Two-time world champion and BBC athletics expert on BBC One

"The women's race has become more tactical in the last couple of miles."

Image source, Reuters

We have an orange vest leading the women's marathon at mile 19. My colleague sat next to me Caroline Chapman does not like orange at all - she told me yesterday. Still there are seven women in contention as they make a left turn and get the full force of clapsticks thrashed together ringing in their ears.

There are horns being blasted, whistles, it's a noisy, noisy affair.

As the men turn a corner to the tune of a brass band on the roadside their stride lengths go unaltered. No amount of tuned percussion can break their rhythm. Eliud Kipchoge looks classy, even with a high-vis headband on. Stanley Biwott - another Kenyan - is on his arm and they are nearing Tower Bride, roughly 11 miles under their belts.

Brendan Foster
Olympic medallist and BBC athletics commentator on BBC One

"Too many of these athletes are going far too fast. This pace is very, very fast."

Image source, Getty Images

Name: Dennis Kimetto

Age: 32

Country: Kenya

Dennis Kimetto stunned the running world in 2014 when he set a new world record at the Berlin Marathon. His mark of 2:02.57 was sensational. 

For those of you who run a 5k from time to time, Kimetto ran each 5k of that Berlin Marathon in under 15 minutes, nearer 14 minutes on times.

His form in 2015 wasn't as hot, injury had much to do with that. But a look at our three Kenyan contenders today hopefully spells out it'll be quite a race.

While the drama of the wheelchair races culminated I can tell you that Wilson Kipsang - one of the favourites for the men's race - fell at a drinks station. He was up quickly and is in the pack of flying machines in with a chance.

The elite men hit 10k in 28:37. Eliud Kipchoge is still leading but there's nothing in it. Some of these men have form over this distance and may hack this rapid lick they are setting. Others, such as Kenenisa Bekele, will have to go where they have not been before in a marathon if this pace is maintained.

Go to the well of pain gents and drink, drink, drink.

Lindsay Barron: Good luck to all marathon runners today. Go on Tim Peake running it in Space! How ace!

Jamie Ogier: They just started the marathon from space. Genuinely the most amazing thing.

Holly Hanrahan: Tim Peake starting the London Marathon from the International Space Station... Amazing!!

Tatyana McFadden is celebrating but spare a thought for Great Britain's Shelly Woods - winner here in 2007. She suffered a puncture and had to pull out. You can watch the sad moment by clicking play.

Baroness Tanni Grey-Thompson
Ex-British Paralympic wheelchair racer on BBC One

"At the moment McFadden is unbeatable."

Image source, .

Another wheelchair race, this time the women, another tight finish down The Mall. The American Tatyana McFadden has done much of the work throughout this race and she's being asked a question or two by Switzerland's Manuela Schar now. Schar threatens, McFadden goes again, she takes it in 1:44.20.

It's her FOURTH straight win here.

Our elite women are hitting the business end of the race, reaching 15 miles in one hour 21 minutes and change. Mary Keitany of Kenya is still fronting proceedings, she has a lot of company but seems to like front-running rather than drafting in behind rivals. It's a display of confidence for sure. The question is, how much are those tucked in behind her conserving and can they find another gear when things get tasty in about 30 minutes.

Baroness Tanni Grey-Thompson
Ex-British Paralympic wheelchair racer on BBC One

"That was a fantastic race for Marcel Hug. Four or five miles from the end he looked like he was playing games but when it came to finish it looked like he had a lot left in him. Fantastic race. That will give him so much confidence going into Rio."