Ultras; how good are the times?

Well, I had planned on a long outdoor training walk, but it snowed. So, to ensure that I went at a good pace, I did my walk on a treadmill. The first 15 miles (2:42) were done a good pace (for me). The last 5 were UGLY. But, it is in the bank; nothing but light workouts and stretching from here on in. I think that getting used to warmth is also good as my goal race is in Houston, and around here the temperatures during my training walks have ranged from roughly 15 F to 40 F (-9 C to 5 C).
Of course, the winter Olympic games have started, and that means female speed skaters, with their "relatively large but fit" thighs and butts clad head to toe in tight shiny spandex. And speaking of that: my wife (who, if she became ultra-fit, would have a Bonnie Blair'ish shape), has gotten into working out. I am so proud of her; I even bought her some shiny green spandex tights. She said that she'll consider wearing them.

Back to ultra marathons and stuff: I was blown away that the first place finisher at the Rocky Racoon 100 averaged 7:58 mpm for the 5 loop trail course (which does have sections with roots). His time was 13:16:56. So I did some searching around to see what good ultra performances were like; I was astonished. Here are some examples:
(Sources: http://www.gbrathletics.com/wrec.htm and http://www.americanultra.org/stats/statframeset.htm)

Road Records:
Men
100 mile run 12:05:43 Andy Jones (CAN) Sylvania 09-27-97 (loop road course)
(that is about 7:15 mpm!!!!)
24 Hour run 290,221 meters Yiannis Kouros (AUS) Basle 05-03-98
(that is 180.4 miles!)
24 Hour walk: 216.621km # Claudio Sterpin (ITA) 19 Oct 1986 Milan
Women
100 mile run 13:47:41 Ann Trason (USA) New York 05-04-91

24 Hour run 243,657 meters Sigrid Lomsky (GER) Basel 05-02-93
24 Hour walk 194.758km # Sandra Brown (GBR) 20 Jul 1997 Ware
(note: we walked in the Dutch Walking weekend in 2004; I finished with 88 miles in 24 hours; she beat everyone (including the men) in the 100 mile and finished in 19:18)

Track Records:
Men
100 mile run 11:28:03 Oleg Kharitonov (GBR) London 10-20-02
(6:52 mpm!!!!!!!!!!!!!!!)
24 Hour run 303,506 meters Yiannis Kouros (AUS) Adelaide 10-05-97
(that is 188.6 miles).
24 Hour walk: 228.930kmA ? # Jesse Casteneda (USA) 19 Sep 1976 Albuquerque
226.432km # Paul Forthomme (BEL) 14 Oct 1984 Brussels (W)

Women
100 mile run 14:29:44 Ann Trason (USA) Santa Rosa 03-19-89
100 mile run 14:25:45 (pending) Edit Berces (HUN) Verona 09-22-02
(pending at the time the source was published)
24 Hour run 240,169 meters Eleanor Adams (GBR) Melbourne 08-20-89
24 Hour walk: 211.250km # Annie van der Meer (NED) 11 May 1986 Rouen

What I learned from all of this is that the track really is the fastest surface; so perhaps it is not so surprising that my road and groomed trail PR's are much slower than my track PR's.

(mine: 24 hour walk (track) 101 miles, (unjudged), 24 hour walk (road) 88 miles (judged; one month later than my track race), 100 mile trail (groomed) 29:34 at LeanHorse, 2005).

But my most humbling experience was at the 2005 McNaughton 100 mile trail run. I entered the walking division and got smoked by 2 hours (by an excellent walker). But that isn't what embarrassed me. The course was ten very hilly 10-mile loops on technical trail. I was at 13:19 at the half way; the second half took me 20:57!!!! I took 57% more time to do the second half of the race.

I wondered if that was the biggest collapse in the whole race as I got passed three times in the last loop. But it wasn't. In fact, three people took longer on the second half than I did (I was 27 out of 28 finishers; there were 48 starters). And, the winner collapsed by 54%. The second place finisher was only 15% slower on the second half. The third place finisher was 60% slower on the second half! One person was 105% slower!

I had thought that a hard 50K done two weeks prior to the 100 did me in; it turns out that my slowdown curve tracked more or less normally with the others. It is just that I had an unusually slow half way split for a finisher, though four other finishers were slower and three of these got me on the last lap.