While the Virgin London Marathon is rightly thought of as the worlds greatest fundraising event, it's also important to remember that it is one of the most keenly contested marathon races on the sporting calendar.
As race director David Bedford states: its probably going to be easier to win the Olympics than the London Marathon, looking at the field.
With many years of experience in long distance running, and as a previous record holder of the 10,000 metres, Bedford certainly knows what hes talking about. Watch the videos to see him cast his expert eye over the field
The men's field will be headed by six top Kenyans - including previous winners, world champions and world record holders - who's your money on?
The women's field could see something very special this year, as Paula Radcliffe's record comes under threat, with some outstanding runners going at it.
So, who do you fancy to come away with the win? To find out more visit the Virgin London Marathon website.