You can do a half marathon with minimal caloric intake, but for a full marathon you'll need to eat something. Figure out what you can digest on the run: banana

You can do a half marathon with minimal caloric intake, but for a full marathon you'll need to eat something. Figure out what you can digest on the run: banana, pb&j, Cliff Bar, etc. Remember that some things (weather, etc) are out of your control, and you may have to go slower than you hoped.