The heat is on, which is why British athletes have been training in specially sealed rooms with a string of boiling kettles blowing steam into their faces. The stifling temperatures and claustro-phobic humidity of Beijing are twin terrors for most of the team, but Mara Yamauchi is different. “It’s a great equaliser,” she said.

Yamauchi may become a household name in the next few weeks if Paula Radcliffe succumbs to her fractured femur and the Anglo-Japanese diplomat takes her place as Great Britain’s best marathon runner. The Tokyo-based Yamauchi has been training in St Moritz, wearing several layers of clothes to replicate the expected heat, and is quietly confident.

“It was 39C in Beijing yesterday, but hot and humid conditions will be better for me,” she said. “Last year there were some athletes who have quicker PBs [personal bests] than me but couldn’t cope with the heat. Olympic marathons have been very unpredictable in the past and I think 15 to 20 women will feel they can win medals.”

Yamauchi, who will be 35 during the Olympic Games, is one and while Radcliffe’s preparation has been wrecked by injury, her teammate has left no stone unturned. Unlike Radcliffe, that meant visiting Beijing to sound out the best Japanese restaurants - seaweed and noodles form a key part of her diet - then returning for the test event. “Seeing a course beforehand helps me and I try to memorise it,” she said. “I was surprised I was the only non-Asian athlete who went to the test.” It has already been a good year for Yamauchi. She won the Osaka International Marathon in January, recording a personal best of 2hr 25min 10sec.

She had led at the World Championships in the same Japanese city a few months earlier, only to fade to ninth. “I got my tactics wrong and got carried away,” she said. “I won’t make the same mistake.”

Perspective is provided by the fact that none of the women she beat in January has made the Japan team, but Yamauchi, who is four months older than Radcliffe, is a dark horse for a medal. She will be happy, though, if the spotlight remains on her more celebrated teammate.

“I have thought about different scenarios and there will be more pressure on me if she is not there,” she said. “I had that before when she pulled out of the London Marathon in 2006 and the media attention switched to me. I don’t relish it, but coping with pressure is part and parcel of being an athlete.”

Yamauchi will skip a trip to Macau, the former Portuguese enclave near Hong Kong, next month to stay at home in Tokyo until the last minute. “I took my case to UKA and they agreed,” she said. “I’ll go to Beijing a few days before the race. My aim is to get to the start line without injury or illness and feeling in great shape.”

Radcliffe, no doubt, feels the same.

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