I am pleased but disappointed at the same time. Basically I got to 20 miles in 1h59 and thought that was too fast and might blow up if I didn't slow down. So I slowed a little and when I got to 25 miles I felt OK (tied but OK); it was too late then to do anything; I should have kept it strong back at 20miles. I think also at the 20mile mark the sun was out so I felt a little heat exhaustion.

The stats:

5 km 0:18:19 25 km 1:32:18
10 km 0:36:40 30 km 1:51:01
15 km 0:55:14 35 km 2:09:58
20 km 1:13:54 40 km 2:29:27
half 1:17:57 finish 2:37:51