After 2 hours of running/walking I ate a handful of trail mix then a Kashi granola bar. After another hour I ate another 2 Kashi granola bars (they taste somewhat like cardboard. I stopped at a friend's place for water and had a bit of tomato soup. I was too exhausted to eat more than a couple bites. She gave me some Motrin and drove me home. I managed 4 hours but have decided that a half marathon is a better option for me this year rather than a full marathon.