Subject: RE: Dallas White Rock Marathon : Official Threadg_shotts - 2009-12-14 8:08 AM
When USATF courses are measured, they actually measure the Shortest Possible Route along the planned course. The official measurements will be based on tangents and the inside of all curves. In a crowded road race, almost no one will be able to duplicate this, meaning the distance the average runner covers is pretty much certain to be longer than the certified course distance.
USATF requires a certified course to be measured at least twice, and the measurements have to come out within 0.08% of each other. For a marathon, that's within 110'. From my point of view, I trust certified couse measurements a lot more than I trust my Garmin.
I'm curious about the method they use to do the measurements. Are they out there w/ surveying equipment, on bikes, or doing it online from Google Maps?
I don't expect it to be exactly 13.1 on my Garmin as I know I'm doing some shifting laterally to get around people & not able to hit the apex of each corner, but I don't see how it was less than 13.2. |