this one is easy wrote:
Wouldn't the higher altitude cancel out the effect of the net elevation drop?
Is a BQ worth more at sea level?
I have run St. George several times, and have some honest course sea-level performances to compare it with. So here are the numbers:
2003:
St. George 2:24:47
Richmond 2:31:45
2007:
St. George 2:23:57
St. Jude 2:30:32
I believe my gap between St. George and an honest sea level course is towards the upper end of the scale. I live at 4700 feet, and do a lot of tempo running down a 1-2% grade. When I ran St. George, I did a good amount down steeper grades. Downhill does not beat me up. My track 5000 PR is only 16:19 (no altitude adjustment, done at 4600 feet, maybe 15:37 on the road (certified course) with 1% net drop at 4500 feet is a better indicator), but in 2003 I ran 21:58 in the Alta Peruvian 8 K (certified course) which has 6.7% net elevation drop, all of it very steady. Afterwards my legs were not sore. Instead of taking a shuttle I ran back up to the start. That same year after finishing St. George my legs did not experience any significant soreness.
So the altitude did not bother me, the downhill did not beat me up, and I had a super-gear that would put me out of my bracket when it came to downhill running. St. George was essentially a local race for me (I live 3 hours away), while Richmond/St. Jude involved travel, different climate, and the terrain for which I did not have specific conditioning. With all of that the difference was 6:58 (Richmond), and 6:35 (St. Jude).
I am guessing if I had focused on honest sea-level marathons giving myself time to acclimate, investing some effort into specific terrain preparation, and picking a better course (both Richmond and St. Jude while not slow are not exactly pancake flat), I should have been able to cut that difference to 3-4 minutes.
Going the other way, I have seen many sea-level runners come to St. George with hopes of running an awesome PR that had their hopes dashed by their lack of downhill and altitude preparation. This is especially true for the sub-2:20 guys. The reason, I believe, is this:
Your marathon performance is limited by two factors - leg power, and body resilience to pounding. The slower runners are limited by the leg power more, while the faster ones have so much leg power than they are able to pound their bodies into the ground. The downhill provides a boost for power from gravity. The slower runners happily take it because they are not yet at the limit of resilience. The faster ones do not find it welcome as they already have plenty of power to reach the limits of their resilience.
So I would roughly expect the following conversion between St. George and an honest sea-level course assuming you are able to properly deal with downhill/altitude:
3:10 -> 3:00
2:30 -> 2:25
2:15 -> 2:13
2:10 lucky to hold his own on the St. George course. Case in point, Paul Cummings, 2:11 marathoner could only run 2:15 in St. George, and from what I heard he did not enjoy the experience due to the downhill beating.
