A couple First Descents employees are going to try to find out. Their goal is to run lower narrows 34 times in a day combined, or 17 times each, one time for each program first descents is offering this year. You can see their page here, and donate to FD if you'd like.
Your first thought may be: 17 laps, that doesn't sound like much. I agree, I think they can do more. One of the participants, Wildflower, has a good excuse. He has been involved with his own battle with cancer this summer, and is coming off the couch to perform. So he gets to stay at 17 laps.
I'm not as familiar with the other participant, apparently he goes by Crash, but it seems lazy to me that he is going to perform the same number of laps as the guy who recently had surgery.
So how many times do you think you (and therefore Crash) could (should have to) run Lower Narrows in a day?
Seriously, if you don't know, FD is awesome. If you have extra money, and you don't know what to do with it consider making a donation. They make a huge difference in the lives of young adults all over the country.