* London is one of the “big five” in the elite marathon circuit, with New York, Boston, Berlin and Chicago.

* More than 382,000 people have completed the London race since it began in 1981.

* More than pound;80 million has been raised for charity over the years.

* You have to be 18 to enter; most entrants are aged between 30 and 39.

* Everyone has to pay pound;23.

* The oldest man to run last year was 90-year-old Alfred Gibson; the oldest woman was Jenny Wood Allen, 86.

* In 1997 Antonio Pinto of Portugal set a 2:07:55 course record for men: Ingrid Kristiansen of Norway set the 2:21:06 record for women in 1985.

* There will be 500 portable toilets for competitors en route.

* More than 6,000 race marshalls, 1,500 St John Ambulance personnel, 500 stretchers and 68 ambulances will be on hand.

* Twenty-three water stations will have more than 600,000 330ml bottles ready.

* A runner can lose up to two pints of water an hour through sweating.

* Runners will get through 40kg of petroleum jelly. This, says a spokeswoman for the marathon, “goes everywhere”, between toes, inside legs, under bra straps.

* Five people have died running in the event’s 19-year history.

* Most people finish within six hours, but marshalls can wait up to 10 hours for the stragglers.