Alyson Dixon went through 5k in 17:18, the exact same time as Charlotte Purdue. These form part of the British contingent who trail our African pack who went through 5k around 50 seconds quicker.

Mare Dibaba heads the front pack, last year's winner Tigist Tufa has a zebra-style black/white vest on and she's in there as they pick up a drink on 10k, what's the clocking, 32:43.

American Tatyana McFadden, who has won the last three London Marathons, is fourth in the women's wheelchair race. 

Her 13-race winning streak was broken in Tokyo a couple of months ago.

And in the men's wheelchair race, fellow American Aaron Pike is now out in front. 

Here is the start of the elite women's race - in what Steve Cram calls "ideal conditions for marathon running".

The elite women clocked 16:03 through 5km. Not bad going at all eh? There are seven in a pack at the front of the field, followed by a pack of five from Great Britain who are on for a two hours 25 minute finish at their current pace. That's quick, probably a bit of a feisty start on the part of some of them.   

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

"Dave Weir is racing a smart and tactical race. He hasn’t been on the front too much. The others are scared of his sprint finish."

Britain's Weir is currently third in the men's wheelchair, in a pack of three who are way out in front.

• Name: Gladys Cherono  
• Age: 32
• Country: Kenya

Cherono is making her debut in London, but she's still got plenty of experience behind her.

A 10,000m silver medalist at the Worlds in 2013, she made the switch to marathons last year and hasn't looked back.

In only her second competitive race, she won the Berlin marathon in 2:19:25 which made her the seventh fastest female marathon runner of all time.

Image source, Getty Images

There's a shine to the road as the elite wheelchair race hits London Bridge, David Weir in a good position. This is the halfway stage and a pack of three are clear of the rest, Marcel Hug of Switzerland leads the way, Australia's Kurt Fearnley in second, Weir third.

Image source, BBC Sport

Gogglebox star Baasit Siddiqui on BBC One: "Fingers crossed I should be alright. I know Dad will be sitting watching, I want to get him out here next year. I spend most of my time watching TV these days so I’m not as fit as I used to be."

If you want to take a look at the blind and visually impaired athletes get underway, just hit play. We have a Gogglebox star coming up for you next...

• Name: Mary Keitany
• Age: 34
• Country: Kenya

The winner in 2011 and 2012, Keitany was well-beaten by Tigist Tufa in London last year.

But the Kenyan bounced back to finish first in the New York marathon in November with a time of 2:24:25.

And the mother of three has a special bond with London - she became the the third fastest woman in history when she claimed the title in 2012. 

Image source, Getty Images

The lead women snake towards 5k near Woolwich Arsenal, having clocked 10 minutes and 59 seconds for two miles. Some going. A pack of half a dozen are well positioned and just shaking out the early nerves. 

The expected challengers are there in their droves, Mary Keitany - winner in 2011 and 2012 - looking good at the head of the pack in a beanie hat.

Japan's Wakako Tsuchida and Switzerland's Manuela Schar pip defending champion Tatyana McFadden to the 10km marker in the women's wheelchair race.

In the men's, it was Ernst Van Dyk, Pierre Fairbank, Ryota Yoshida and Marcel Hug who led the men's wheelchair race at the 10km mark.

A quick note on our elite womens' race, Team GB requires a time of two hours 31 minutes if someone is to qualify for Rio 2016 and in addition to that mark, the women must finish in the top two Britons today. Sonia Samuels and Alyson Dixon already have the necessary qualifying time but as per the rules above, they have to race, race, race.

Here's some more inspirational Marathon Stories - this time featuring Stuart, Heather and Orin.

You can still watch yesterday's show A Million Reasons to Run with more Marathon Stories on iPlayer here.

Steve Cram
BBC athletics commentator on BBC One

"They are ideal conditions for marathon running really, especially for the elite. Cool, the sun is trying to come through, seven or eight degrees. Perfect!"

Early on and we have two packs formed straight away in the womens' race. The Kenyans form the brunt of group one, the Britons group two. Mare Dibaba leads the front pack, who clocked around five minutes and 25 seconds for mile one.

Brendan Foster
Olympic medallist and BBC athletics commentator on BBC One

"We've got virtually two races here. We've got them wanting to win this race and there's a race for the Rio Olympics."

There's a lot at stake here, the African contingent racing for the win, a number of Britons seeking an Olympic place. Charlotte Purdue is among them, her first marathon at just 24 years of age. Purdue was sixth over 10,000m at the 2012 European Championships.

Of course, that "slowly does it" advice I've just dispensed does not apply so much to the elite women who are on the start line right now...

If you're reading this ahead of the race then I salute you.

Keep the nervous energy in check and when the gun goes to start things off, put the brakes on, don't let the adrenaline send you off at a crazy pace. You want to steal the early stages, put them in your pocket for free, with little energy spent. Save it, stash it and unleash your fresher legs late on.

Go for it, I'm excited for you, goodness knows how your feeling inside. Enjoy it.