“Net downhill” is somewhat synonymous with “fast”. In road running, there are regulations in place that limit how much drop a point-to-point course can have before it becomes invalid for record purposes. Boston, a generally fast marathon—mostly due to its qualification purposes—is aided in its relative speed due to a –447’ net elevation. It’s too downhill for records purposes. When Geoffrey Mutai ran 2:03:02 in 2011 it was the fastest marathon at the time, but not a world record.
Trail running is a different story all together. While trails vary widely, they generally favor the uphill. Black Canyon 100K is not like that.
I underestimated it. Don’t make that same mistake.