IT is a truth universally acknowledged that if you can’t stand the heat you should get out of the kitchen. Not so for Mara Yamauchi, the Oxford-born Brit with the Japanese husband, Tokyo base and CV that includes interpreting for Baroness Thatcher. Her present incarnation is as a leading marathon runner in a country that is marathon-mad.

Yamauchi’s surname is attracting attention in her adopted homeland. Meanwhile, a Britain awaiting the return of Paula Radcliffe from maternal duties will wonder whether the former Miss Myers can use her insider knowledge to fill the biggest void of all in the World Championships in Osaka, Japan — where the searing heat and high humidity will have a huge bearing on the result.

Yamauchi, who is on leave from the Foreign Office until after the Beijing Olympics, knows the chances are slim and the standard vertiginous. “One of my Tokyo club-mates who I train with ran 2 hours 24 minutes on her debut and she is only a reserve,” she said. “Had Mizuki Noguchi been there she wouldn’t even have been first reserve! The quality is there, but the weather will make a lot of difference. Championship races are always slower and this certainly will be. People like me, part way down the field on paper, have more chance than in any regular city marathon. There will be surprises and I hope I’m one of them.”

It is alarming that the likes of Noguchi have decided to skip the World Championships because of the conditions, but it does create more opportunities for those whose bodies can withstand the heat that reached a record 40C in Japan recently.

Yamauchi, a 34-year-old who has lived in Japan for six years, was eighteenth two years ago in Helsinki, but is in better shape this time. Sixth place in the London Marathon was a milestone on the road to heightened optimism and her best time is now 2hr 25min 13sec. That, she expects, would win gold on Sunday week, the last day of the championships, but it will not be that simple.

“Osaka is a bit warmer than Tokyo and more humid because it is positioned in a natural basin,” she said. “A lot of distance runners in Japan move to the north of the country or to one of the northern islands in summer to get away from the heat. Many go abroad to escape it. None stay in low-lying areas like Osaka.” Which might make you wonder quite how the World Championships happen to be taking place there in August.

Yamauchi has joined the exodus but has also tailored her training to fit the 7am start time. “I have just spent a month in St Moritz — for the high altitude first, but also because it’s cooler. You can run in the early morning or late evening, but the humidity is such that even normal life can be very draining.

“Since I’ve been back from St Moritz I’ve been getting into the habit of getting up at 3am, breakfasting at 4am and running at 5am. I thought it would be quiet, but you wouldn’t believe how many people there are, cycling, jogging, walking, skateboarding, playing golf because the rest of the day is so hot.”

Yamauchi has long been overshadowed by the nation’s love-in with Radcliffe, but she believes that in normal conditions she is now in 2hr 23min shape. She has had the benefit of running most of the course, which she describes as fast with few hills and scenic sections but for a loop around Osaka castle, and there will also be support from the public.

“Athletics is very popular and the marathon is the most popular event,” she said. “The Japanese have high expectations. The ticket prices are high, but in spite of that, the Japanese take pride in hosting an event, as they did at the World Cup, and they will turn out. I’ve got a Japanese surname so people generally here will give me a bit of support.”

Yamauchi, married to a lawyer named Shigetoshi, runs for the Second Wind club in Tokyo and will only arrive in Osaka on Thursday week, but advises her team-mates to “keep out of the summer” and “not do anything crazy”. She believes the marathon, the walks and the 10,000 metres will be dictated by the weather, but that the other events should pass off without the risk of dehydration or the times when “your body heats to a point where it will not function”. However, before anybody gets too encouraged by that appraisal she sounded another stark weather warning. “It might be windy too,” she said. “It’s the typhoon season here.”