September 23, 2007
The first (and only!) six hours
I took two quarts of fluids with me on the first lap. Based on the pre-ride measurements, that would keep me close to hydrated. I also stayed topped up well the night before (not with beer) and drank a quart of Gatorade 20 minutes before the race started. I felt slightly full, a feeling that I don't like, but have come to expect before a long race.
The 1st lap went to plan. My pace was a little too high on a few occasions when I was trying to stay out of other rider's way on singletrack. They started the teams 5 minutes behind us and they caught me on the first singletrack section. After the first lap things strung out and it was easier to work out traffic issues. I finished it at 1:30 - I was on schedule.
But the plan was wobbling a bit. I lost my water bottle in some bumps early on the course so I didn't have the proper quantity of fluids. My Camelback was still there though and supplementing from water and Gatorade that was being handed up at two stations along the route offset the lost bottle a little. I didn't make up the entire bottle's worth. I also didn't weigh myself at the end of the lap because I felt OK, hot but not bad.
I increased the fluids for the second lap to make up for the lost bottle and I drank most of an extra bottle on the short paved section around the pits that I tossed back to Ray before heading out on the course. Having that bottle temporarily along with a cool towel on the back of my neck was in the plan for the first 6 hours. I had to drink it on a schedule and I didn't have to carry it up the hills.
About a mile into the second lap I started cramping. I'd actually picked the spot I thought I would cramp the lap before accurately. It wasn't intentional; the thought just came to me as I rode through the section. I didn't think it would happen on the second lap though. I was drinking so much I was feeling very bloated and burping Gatorade back up.
The cramps clearly showed I was getting behind on fluids. The bloat meant my stomach wasn't draining quickly enough. It was less than 2 hours in and my plan for hydration and pace wasn't working because of some physiological process I didn't account for - the slow rate at which the fluids I drank can get past my stomach and where they need to be.
I slowed down so I could drink as much as I could and let it get in and through me (there is a weak relationship between exercise intensity and gastric emptying). I also stopped twice at the feed stations to drink a little and let it soak in. It was very hard to get the liquids down because I was still feeling bloated. There is no simple way to force that short of an IV. I was also starting to feel slower on the bike, a consequence of dehydration I am a little too familiar with. I got through the lap in 2 hours and checked my weight - I was down 4 pounds, and still feeling bloated. There was a lot of water in me, but it was in the wrong place.
I sat for 10 minutes with a cold towel on my head, ate a little, drank an electrolyte dense drink (Pedialyte - ummm, tasty...) and went out for another lap. The bloat got worse and I started to have an upset stomach. My legs felt a little better though (the electrolytes kicked in) so I picked it up just to see what would happen. I cramped occasionally but not in the deep way that kills my legs and got through the lap in 1:35. That was better.
Then I weighed myself again. I was now 7 pounds lighter than when I started. That's over 4% of my body weight lost and since some of the fluid was in my stomach the state in my muscles was worse so I stopped. I've been through this before - it is not an issue of determination or will. I needed to get my weight back up before I rode again. 24 hours with cramps at half power would not work.
That's when the next physiology experiment started.
I got one quart of Gatorade down with some difficulty. Then another. It took an hour to do that because of the bloat and upset stomach, and I needed 4 quarts total. I gained 3 pounds back. But I was still cramping and the skin pull test on my hand showed that I was still in a very dehydrated state. Then I peed and lost a pound back.
Another hour, another 2 quarts, some of it peed back out.
I was peeing clear, but the fluids were passing through me and I was still cramping. I could walk without cramping, but I could induce cramps easily in my calves and hands. With all the experience I have I know how to do this now. My weight was up 3 pounds and seemed stable there, but the fluids were not getting to my muscles very quickly.
I figured it was going to take too long to get back to a reasonable state and race again so I pulled out of the race. I was hoping the steps I had taken would have prevented this, but they didn't. Riding in heat is going to take more than a reduced pace and increased fluid intake. The rate at which one processes fluids through the gut and then how long it takes to get into muscles seems more complicated than I would have guessed, in my case anyway.
I am bummed, but not devastated. It was another experiment to see if there was a way I could get along in the heat. Checking the race report I wasn't the only one to come unglued in that weather. The heat caught up with some of the other racers too.
I do have one bitch about the race. MP3 players were not allowed, not even if you were using one earpiece. The organizer said that it was due to insurance regulations so I didn't argue. (I did complain, but in a friendly way). This is silly. I hope it is not something that becomes the norm.
On a high note the prototype tire I was testing worked. It's a very fast rolling knobby with small, widely spaced knobs, a minimal XC racing tire in every respect. I had ridden a similar Conti tire for years, but only on a few courses. It was like a road bike tire in many respects, but could not take the punishment most off road courses dished out. This new tire has the same sort of fast rolling properties but solves the durability problem with a minimal weight increase.