She was the golden girl of British athletics and carried a nation's hopes on her shoulders, but it all ended in tears. Nick Morrison looks at how the burden of expectation left its mark on the most talented distance runner of her generation.

IT shouldn't have ended like this. She should have entered the horseshoe-shaped Panathinaiko Stadium, birthplace of the modern Olympic Games, to be saluted by the world as the greatest female distance runner of all time. Instead, she finished the race sitting alone by the side of the road, tears streaming down her face. She arrived at the stadium in an ambulance.

Since long before the spectacular opening ceremony signalling the return of the Olympic movement to Athens, Paula Radcliffe has been a gold medallist in waiting. Twice she has destroyed the world marathon record, taking apart world-class fields with her characteristic front-running, in both London and Chicago, to add to her European 10,000m record.

Anyone tuning into the BBC's coverage of the Games must have assumed that, such was her dominance of the event, all this Radio Times cover girl had to do was turn up and she would be crowned Olympic champion. Television listings even gave the time she was expected to enter the stadium, to make sure viewers could witness her moment of glory.

The stunned reaction of the commentators as she first stuttered and lost ground on the leaders, and then stopped completely, only to restart and then stop again in a heartbreaking struggle against the inevitable, is evidence enough of the expectation riding on her shoulders, expectation which ultimately she proved unable to bear.

Not surprisingly, initial blame has fallen on the conditions. By running the marathon in the late afternoon, the organisers had condemned the competitors to heat of 35 degrees C and energy-sapping humidity. Radcliffe was one of those who had called for the event to start at 6am, but to no avail.

But Radcliffe has refused to blame the weather for her collapse. In her first post-race interview yesterday, she said it was not the conditions at fault, she just had nothing in her legs.

As Games organisers have pointed out, the athletes were all aware of the conditions, and Radcliffe is known for her fastidious preparations. Illness remains a possibility: in her interview yesterday she said she was waiting for test results from a medical; indeed, few other explanations could account for such a dramatic fall from hot favourite to being unable to even finish.

But an alternative is that the pressure proved all too much: pressure both from a nation desperate for an athletics triumph, and from her own hunger for a medal. Four years ago in Sydney, she was leading the 10,000m with a lap to go, only to finish fourth, generally acknowledged as the worst result, just missing out on a medal.

Radcliffe was also in fourth when she dropped out on Sunday, having just been passed by the Ethiopian Elfenesh Alemu, and the prospect of again coming agonisingly close but going home empty-handed must have seemed too much to bear.

In her interview with Radio Times before the Games, Radcliffe had denied that she felt outside pressure. "The only pressure I feel is really my own pressure and my own expectations," she said, but it would be hard indeed not to be affected by the hype surrounding her.

But even with this pressure, and even with the hostile conditions of running in the glare of the Greek sun, it may have all proved manageable if her race plan had not fallen apart.

Wise to her tactic of running away from the field from the start, the other contenders stuck with her, and it may have been the realisation that she had not opened up the gap she thought she would that sowed doubt in her mind.

"If you are used to running at a fast pace and getting away from the pack, and then you have a pack right behind you, you realise that your tactic isn't working," says Dr Joan Harvey, chartered psychologist at Newcastle University.

"Then you are overtaken by three other runners and you see them going into the distance, and that is a massive psychological problem for you. She must have realised she was going to come in a lowly place and that was probably what toppled her."

Although Radcliffe was not the only British hope for gold, she had been singled out as the one to watch, perhaps a combination of the position of athletics as the most cherished of Olympic sports and of her image as a determined runner not afraid to pass through the pain barrier.

"There has not been the expectation on other people as there has been on Paula Radcliffe. Ben Ainslie won gold and is one of the best sailors in the world, but we didn't hear about him all the time," says Dr Harvey.

"She was carrying expectations beyond her capabilities, and that is very difficult to bear, and she had expectations of herself. She is number one in the world, she expected she would be the one to beat.

"She has been hot before and she has been exhausted before, but there was this mountain of expectations and she was watching people go past her and the will suddenly left her."

Although conditions were undoubtedly extraordinarily difficult, both Britain's other two athletes in the race, Tracey Morris and Liz Yelling, finished the race, despite not having either Radcliffe's ability or her dedication. But for Radcliffe, finishing well down in the field was just unbearable.

There is also the possibility that she and her team misjudged the conditions, and she did not take on enough glucose and water before and during the race. Low blood sugar and dehydration may well have affected her brain, impairing her decision-making.

To admit her preparation was at fault, even if by only a small margin, may satisfy the need for an explanation, even if it seems unlikely for someone known for leaving nothing to chance.

"We all want to know why this happened, and if we don't get a reason then everybody will make one up, including her. We're looking for a reason for things that happen, and we aren't comfortable without reasons. Even if they aren't the right ones, we would rather have them than nothing at all," says Dr Harvey.

Now, Radcliffe has to cope with being the favourite who failed, which could be just as much a burden as the bearer of a nation's hopes. The 10,000m on Friday may be her only chance of an early redemption, although she has still to decide if she will take part, but otherwise it will be as long and hard a road as the route from Marathon to the Panathinaiko stadium.

"If the reason is that she just made a mess of it, you have to reinstate yourself, and the quickest way to do that is in the 10,000m. If she doesn't, the next Olympics are a long way off and in four years time it is going to be about 'Will she finish?'," Dr Harvey says.

"A good result in the 10,000m would get her out of this and restore her faith in herself and our faith in her, but if she doesn't she has a long struggle."

And while the decision to give up on Sunday may have seemed the best one in the circumstances, it may be one that returns to haunt her, Dr Harvey adds.

"If she thought it was gold or nothing and she opted for nothing, the danger is that nobody is ever going to think she can do it. Now she is the favourite who gives up.

"It was not just her legs, it was what was going on in her head once she knew she was not going to catch them. At that point, giving up was easier than keeping going, but psychologically keeping going was the better long-term strategy. It is very hard to justify packing up."