Rim2rim2rim day hikeMarch 25, 2009 went with 2 other dudes rim2rim2rim in a day. We debated about the best time to leave first thinking about trying to time it so that both uphill sections would be done in the dark and then switching it up to put the descent of the north rim in the morning. The reasoning behind this was not all of us had been on the north rim and we were concerned about missing a switchback in the snow and falling off a cliff at night, to achieve this we left at 8:50pm. Turns out there were only patches of snow on the north rim. This timing put our ascent of the north rim between midnight and about 5am.
The last couple miles up the north rim I had the overpowering desire to stop and go to sleep, seriously if I was by myself I may have, I'd never really had to fight the (circadian) rhythm that hard before.
I decided to try Gu energy gel for this trip as I was afraid of running out of glycogen and hitting a wall, marathon runners, (which I'm not) are supposed to be able to hold 7 Megajoules of energy in glycogen and for a 90kg person (me) an altitude displacement of 22,000 feet equates to about 5 Megajoules assuming 100% efficiency (which the body obviously is not, this should be balanced by the fact that going downhill requires only half(<-wild guess) the energy of going uphill). While it's hard to tell how effective it was at delaying "the wall" one noticeable effect that I didn't expect was I never got that lactic acid muscle burning feeling that I got on other long day hikes and while working out and stuff.
I filled my camel back with gatorade and I think I OD'd on electrlytes a bit as I tried hard to stay hydrated and drink even when I didn't feel like it, my stomach was upset for the whole last 3/4 of the trip. GAtorade plus Gu is a lot of potassium and sodium.
1/2 way through I found myself craving normal food like... a sandwich... rather than the energy bars I usually bring on these trips. I'm not sure why this is but I do think my body was telling me this for a reason, perhaps I'm wrong.
Our goal for this trip was to beat 20 hrs and it turns out this goal was a little weak as my total time for the trip was 17 hours and 55 minutes, which I'm pretty proud of. Marathon dudes that run it seem to take about 14-17 hrs though I read somewhere that the record is 6hr 59min. Wow!. Despite this it's still my longest ever single push, Whitney was 8 hrs (4hr 24min. up, 45 min at the top and fast down)Hualapai Hilltop to the Colorado River(via Havasupai) and back was 15 hrs.
Overall it was a great trip but I ain't doin it again, once was quite enough.
Edit: This is a duplicate trip report, I couldn't figure out how to make it show up under the Rim2Rim2Rim category originally.