And when she returned from that mammoth - and curiously pointless - odyssey, it seemed she had got no nearer to being at ease with herself. Unlike the journeys of, say, Alison Hargreaves, the adventure seemed to offer her no satisfaction - and thus diminished our enjoyment of it.
When the news emerged yesterday that she had confessed to sitting in her back-up van for 1,000 of those miles, I expected to like her even less. It's cheating, after all, and as footballer Diego Maradona and sprinter Ben Johnson discovered to their cost, no one likes - or forgives - a cheat.
And yet, somehow Ffyona Campbell has suddenly become a more interesting and sympathetic figure. There can be no one who hasn't cheated at some point, no one who, despite their achievements, hasn't waited for that tap on the shoulder.
Ffyona cheated, according to her autobiography, because of the pressure on her to succeed - from her sponsors, the public, and, more importantly, from her father, whose approval she "lived" for.
Endurance walking was the only thing to give her a sense of pride: when an unplanned pregnancy meant that she could not do that, she cheated because she could not bear to fail.
"I destroyed the only truth around which my own sense of right and wrong had pivoted and, since I could not trust myself, I wasn't able to trust anyone else," she wrote. No wonder she proved a difficult heroine; her spikiness was an understandable reaction to the knowledge that she hadn't done the very thing for which she was being lauded.
And now, after a more than a year of agonising secrecy, she has unburdened herself. "The truth is hard enough to live with but deceit is even harder. Once you've lied about your achievements, you've created a burden for yourself which you can never, never put down," she said yesterday.
Few people have not experienced that blinding relief at having confessed - whether it be the errant husband or the exam cheat.
Some, however, cannot bear the public disgrace and suffer unimaginably. Earlier this year the US Navy's top admiral, Mike Boorda, killed himself after questions were raised about medals he may not to have earned. For him, his massive achievements, so much more important than the relatively trivial nature of his deception, had become irrelevant.
And so it is with Ffyona. Those 1,000 miles were just a small proportion of her astonishing feat - she even went back and walked them recently alone and in secret. Yet even that act of contrition was not enough. Her deception had sullied everything else to the point where it nearly destroyed her. She had to come clean about what she had done. Who says our society has lost its sense of morality?