A MATHS teacher has swapped brain-power for paw power and broken a world record for running a marathon while dressed as a dog.

Guinness World Records has confirmed Fiona Betts, 44, smashed the previous record by more than 13 minutes, despite gruelling heat at last week’s London Marathon.

The canine competitor, from Upton, near Didcot, is now the proud record holder for the fastest female to run the London Marathon in a full body animal costume.

A teacher at Moulsford Prep School, near Wallingford, Ms Betts was inspired to run the marathon to raise money for Hearing Dogs for Deaf People, a national charity that trains dogs to alert deaf people to everyday sounds.

Despite facing competition from a fellow runner dressed as a horse and record high temperatures, she ran in four hours, 13 minutes and 25 seconds, beating the previous record of four hours and 21 minutes and raised almost £2,900 for Hearing Dogs in the process.

Ms Betts, said: “When I finished the race I felt exhilarated, exhausted and emotional, and when I realised I had beaten the world record I was stunned as I wasn’t expecting it at all.”