I'm thinking about doing a Saturday marathon in October, followed by a Sunday marathon the next day. Anyone with experiance in this have any tips? I can register for the Sunday one Saturday night, so I'm planning to register last minute only if I feel up to it, but I'm looking at how to best feel up to another one after running the first. I figure back to back long training runs would be a place to start, and maybe taking the first race kinda easy.