Virgin London Marathon 2013: Foamy and friends take on the Guinness marathon challenge

Jerome Timbrell has completed 34 marathons since he started running four years ago, but it's his incredible stories, and famous alter ego ‘Fire Marshal Foamy', that really capture the imagination.

Timbrell, a safety officer, was taken hostage in an armed robbery in Belgium 14 years ago when gunmen burst into the warehouse where he was working to steal some of the store's £12 million-worth of computer parts. The bungled heist turned into a stand-off with the police, and Timbrell found himself bundled into the back of a vehicle and dumped in a wood.

He suffered post-traumatic stress disorder and became so over-weight that he was unable to walk without pain until he had gastric bypass surgery in October 2008.

Gradually, he turned his life around. He ran his first London Marathon in 2010, finishing in four hours 43 minutes, an achievement he "moderately enjoyed". Soon, however, he was passionate about running and started doing a marathon per month, losing 12 stones in the process.

Clearly, a monthly marathon wasn't quite enough of a challenge, however, so Timbrell has added the extra complexity of fancy dress for the 2013 Virgin London Marathon.

‘Fire Marshal Foamy', his fire extinguisher alter ego, is the official mascot of Jerome's health and safety business, and he's targeting the Guinness World Record for fastest marathon by a mascot, which stands at 4:16:43.

"The beauty of Foamy is he makes people smile, especially small children," said Timbrell. "The credibility for Foamy is that if he gets this world record the kids will start listening to him - me - when I tell them not to play with fire."

Olivier Hamar will cut an equally striking figure when he runs dressed as Napoleon in a bid to break the record for fastest marathon in full military uniform of 3:49:21.

The Frenchman, who has a lifetime best of 2:59 without fancy dress, ran the London Marathon for the first time in 2011 and was so impressed with the colourful costumes that he vowed to join in.

"I knew everyone on the course would know him, so that's one of the reasons I chose him," said Hamar. "My costume weighs about eight kilogrammes so I think I might suffer a bit, but I'm aiming for around 3:30 to beat the record by around 20 minutes.

"This time I won't run for my family or friends, I'll be running for Boston. I'll be wearing a fourth medal in their memory, the medal I got when I ran in Boston years ago."

Among the other Guinness World Record attemptees is Peter Knight, running for the Stroke Association. To become the fastest marathon runner dressed as a bottle, he has to run quicker than 3:39:25.

"I've done three London Marathons before and I wanted a Guinness World Record I could challenge," he said. "I looked at batman but his time was ridiculously quick. I then worked backwards and found the bottle."

Mark Anslow and Chris Wheeler are attempting records as the fastest marathon on crutches and the fastest dressed as a chef.

Anslow picked up a stress fracture six weeks ago, but opted to attempt the race on crutches rather than disappoint his sponsors, and charity, Whizz Kids, by pulling out. He will make his debut this weekend aiming to finish quicker than 6:24:48.

Wheeler won a Capital FM competition to run alongside their breakfast team to raise more than £10,000 for the Help a Capital Child Charity. He is aiming to finish in less than five hours, carrying a stockpot to qualify for the record.