Runners can qualify for April's Boston race, the world's oldest annually contested marathon, with their performance in other sanctioned marathons.
Now, at 32, Petrova is back in America as one of the favorites in Monday's 105th Boston Marathon, the world's oldest annually contested marathon.
But it wouldn't stand as an official world record: despite being the oldest continuously contested marathon in the world, Boston does not count for world record purposes.
Mr Clegg is in the middle of a marathon bus tour of closely contested races across the UK, but Sheffield Hallam is his home constituency, which he has represented in Parliament for 10 years.
"But in the meantime he's not getting to test himself against his American rivals," said Rainsberger, who noted that Chirlee did not run in the national half-marathon championships Jan . 29 an event contested on the course where the Olympic trials will be held.
The highlight of this unfortunate episode came in the 400m final, which was contested the day before the marathon by three Americans and a single Briton.
It was the closest marathon finish in the history of the world championships, which are being contested for the eighth time and for the first time in North America.
The mayor of Jerusalem, Nir Barkat, has described the marathon, in its third year, as an effort to make his bitterly divided and contested city "normal".
The Olympic event, contested first in Sydney in 2000, is much shorter than the Ironman, whose running leg is a marathon.
Such an impressive performance on a warm day might put her in contention in the women's marathon at the 2004 Summer Games in Athens, where the course is largely uphill and unshaded and figures to be contested in brutal heat.
