Charity fundraiser Lloyd Scott, who has helped raise millions, has vowed to continue after revealing the "devastating" break-up of his marriage.
The 44-year-old - famed for completing the 2002 London Marathon in a deep-sea diving suit - described how his world "fell apart" after discovering his wife, Carole, aged 41, had been having affairs with two of his friends.
He believes she may have used his charity stunts to meet partners, but added: "When I do my charity endeavours my family are an integral part of them - to say I go off and leave them wouldn't be fair.
"Hundreds of thousands of people get divorced, you wouldn't have to do a marathon in a diving suit to get divorced.
"My wife was unfaithful to me in our first year of marriage. She wasn't driven into the arms of another man because of the charity work.
"Sure, I'm aware it put a bit of a strain early in our relationship, but I like to think I learnt from that and did my utmost.
"All the projects had the approval, consent and encouragement of all my family, both my wife and my children."
The fundraiser claimed that after his wife's first affair, he discovered in 2003 she had started a relationship with Rob Fitzgerald then, after he thought they had resolved their problems, another one with Tony Mercer.
She confessed to the final affair on Christmas Eve last year after his suspicions were raised when she sent a text to her parents which ended "love Carole and Tony".
By the time Mr Scott completed the London marathon in May, dressed as St George in a suit of armour and hauling an eight-foot dragon, the couple, married in 1986, were going through divorce proceedings.
Father-of-three Mr Scott, from Rainham, Essex, has raised around £5 million through charity stunts, from a 2003 underwater marathon in Loch Ness to cycling 2,700 miles across Australia on a penny farthing in 2004.
Last year he swam from John O'Groats to Land's End in a tiny tank fixed on an articulated lorry and runs a London triathlon on Sunday.
The fundraising efforts of the former professional footballer and fireman began in earnest after he was diagnosed with leukaemia in 1987 and within 12 months had run a marathon.
He said: "It's been pretty devastating. People have said I have been strong to come through illness and charity challenges, but this is completely different. I'm still very, very upset."