I did my first PPM last year, and signed up for the Double this year. Last year I flew in on Saturday and did not have (much) trouble with the altitude. The next day when we drove up to the top I could barely walk from the car to the gift shop. I'm not sure if that was because of the extra day at elevation or because we got up there quickly in the car compared to the slow trudge up on foot. I'm just wondering whether I can expect to feel worse during the marathon because I've been at elevation longer. I'd especially like to hear from flatlanders who did the Double. I get in Friday afternoon. Thanks in advance!