In a few days' time, Kleanthous will join 49 like-minded fruitcakes and swim up and down a French open-air pool for 7.5 miles. He will come out of the water, jump on his £3,500 titanium bike and cycle for 336 miles (about the distance between Liverpool and London). Nicely warmed up by now, he will drop the bike and round off with a triple marathon of 78.6 miles. lt will all be done without a break to sleep, eat or even to pee. I tell you, we're taIking seriously deranged.
Welcome to the rarefied world of the super-sportsman. Unfulfilled by the legendary lronman Challenge (2.5-mile swim, 112-mile cycle ride and a marathon) started on Hawaii almost 20 years ago, this lite set now need a Triple Ironman to get their kicks.
Kleanthous has already completed two Double Ironman (or should it be Ironmen?) but he is apprehensive about the triple, which starts in Grenoble next weekend. Not about the swimming or cycling or running - that's the easy bit. "My biggest problem will be lack of sleep. I have never stayed awake for 40 hours," he says.
What would you expect an ironman (sorry, triple ironman) to look like? I envisaged a mix of Batman, Geoff Capes, Christopher Reeves and Popeye. Instead it was a slender, almost skinny pipsqueak of just 5ft 6in who met me at his semi in Wing, Bedfordshire. No wonder his support team for last year's World Double Ironman Cham-pionships in Huntsville, Alabama, wanted to chop him for someone more, well, substantial.
But there's no sign of that yet. Kleanthous still has an unfulfilled dream or two - including the ambition to run from coast to coast across America. What about the Quadruple Ironman being mooted later this year in Mexico?
"No, that's just silly," he said.
But Kleanthous, all 9st 3lb of him, gave those good ol' boys a nasty ol' shock. He set a British record by finishing just inside 24 hours and came sixth, beaten only by a few professionals. Slight he may be, but slight him at your peril. There can be few fitter men in Europe.
Kleanthous has finished 65 marathons, two double mar-athons and a 100- kilometre race. He has cycled the 874 miles from Land's End to John o'Groats in five days. He's done 1,000 press-ups in 27 minutes, 30 seconds. He even came third in a race up London's Post Office Tower, taking under five minutes to climb the 900 steps.
What drives this extraordinary man to push his body through such extremes? He's a business development manager for a food marketing company and, at 33, he really should know better.
"You seem like a man possessed," I say.
"Yes, I would have to agree," he admits.
Searching for his motivation, he says: "I'm very aggressive and competitive. I like to win at everything, whether it's sales incentives, cards or running." But that doesn't really explain the demon that drives him to complete two triathlons in a day, to spend much of his money (entry alone for the Triple Ironman is £226) all his holidays and much of his spare time swimming, cycling or running.
lt probably all goes back to school in Dagenham, Essex, when he finished last in a cross-country race. Even then, he was small for his age (he went to the same school as Dudley Moore) and the mocking words he got from his classmates made him determined that it would never happen again. He started running seriously, and three years later represented the school.
"My lack of natural ability was hidden because I trained so hard," he said. "I was under 16, but I was running 40 miles a week." It continued when he left school to work in the city of London: "I ran the 15 miles each way daily. It seemed silly to get the train there, and I didn't have to pay any fares or get caught up in traffic."
Kleanthous trained hard for the first London Marathon, finished in just over three hours and, in his own words, "really caught the bug then." He ran every marathon he could find and got his time down to 2 hours 24 minutes, then realised that he had no further to progress. "I couldn't improve any more. I had reached my natural ability peak. It was a bit depressing."
Then like a child discovering chips, he found out about triathlons. "I was eighth out of 400 in my first one, but I wasn't much good at swimming or on the bike, so I started to work on these. In triathlon you don't have to be fast, you have to be efficient. People always ask: 'What do you think about for hours on end?' But that's not a problem. You can't let your mind drift off. It's constant concentration. I think about my position, my style, and so many other things such as whether I'm eating enough."
Food. . . there's an interesting topic. Kleanthous has calculated that he will burn up 24,700 calories during next week's race. He averages nearly 5,000 calories a day anyway. "When I go shopping, people say: 'Goodness, you must have a large family.' I eat 90 per cent of the food in our house. I'm always eating. I entered a local competition where I ate eight and a half pizzas in an hour." His girlfriend, Clare, adds: "He will get very fat when he stops it all."Reuse content