to quote the great Ali G - "Science.... wot iz it? Techmology..... wot iz it all about?"
come on folks time to use some modern science and technology (weather data, google earth, ncaa xc race/athlete history, and common sense - aka logic, even a bit of anecdotal observation wouldn't hurt) ... 2:29 were the very first guys, midway through the field was about 2:35, it was >9m/30ft net downhill, half of it low gradient (comfortable downhill speed maintenance), half flat, they all have super shoes which no doubt help the impact going downhill, they had a small tailwind from the north (was NE pre-race NW post-race, recorded in both Earlysville and Charlottesville), and course conditions were generally fast. The guys at the front could all handle a 2:40, as for most that's about 5k pace,... so if all of this stuff doesn't add to 10sec then who cares, because its highly probably it adds to at least 6 seconds (2:35-36), and much of the field around equivalent of 2:42 or slower. Plus it all depends on mentality of the guys racing as to how they approach it or feel about a fast pace. Clearly, it didn't work wonders for all, nor entirely compromised others' races, so its likely it was a RELATIVELY fast 1km for a reason.
class dismissed.