I've gone over the race several times in my head, and Tim Noakes new book, Waterlogged (iRunFar.com review here) seems to have come out at an apt time for me. I truly believe that drinking more water was not an option for me. My stomach was full and could only absorb so much water during the race.
After considerable thought and research, I've narrowed my problems down to four chief items:
1. Pace. I ran miles 6-17 too fast. No doubt about it. I passed a lot of people in those 12 miles, and most of them passed me back on the second lap. I spent two hours running harder than I should have, meaning I couldn't drink as much as I should (because blood flow was in my limbs and skin, not my stomach), and my body temperature was rising fast as we headed into the hottest part of the day. I was frustrated by the slow pace of the crowds on the trail, then overcompensated until I blew up.
2. Acclimatization. I'm not sure how much of a part this played, but I certainly didn't have the same kind of hot weather training that I've had in previous Junes. I've written before about the benefits of hot weather training, and I think if I just had taken the time to put on a warm hat or long-sleeve shirt before some noon-time runs, I might have been better prepared for the Finger Lakes Fifties.
3. Cooling Off. Your body can only do so much to reduce your body temperature, so on hot days, it pays to find other ways other than sweating to cool off. There was ice available at the aid stations, that I don't think I made the best use of - I rubbed it on my neck and held onto it to cool my skin, but I didn't get any lasting benefit from doing so. I think using something like a Cool Off Bandana would have better utilized the ice and kept me better moving towards the next aid station.
4. Fitness. I'm definitely not in the same kind of shape I was in last summer. I'm about ten pounds "overweight" (over racing weight, that is), and I didn't have more than fifty miles in a week of training since last fall. Simply put, if I weighed less and was in better shape, I could have been more efficient on the trails and my body would not have heated up as quickly. It's not exactly earth-shattering to say that good training will make you a better runner, regardless of the weather.
I think the two major factors were 1 and 4 with 2 and 3 playing smaller roles. And unfortunately, those were both "rookie mistakes". I know better than to go out too fast (granted, predicting pace on a hot day is tricky with a 5K, let alone an ultra), and I also knew that I had weight to lose and miles to put in that I just plain didn't get done.