Hey! I've ran a marathon and a few other long distance runs. I'd like to see what info you get.
I went with Sport Beans for my long runs, and for the races, and I really wish I hadn't. I'll tell you that I think that and the gatorade really jacked with my stomach. I had horrible stomach cramps that I've never had before. I will be searching for better alternatives for this season for sure!! I've added some sweet potatoes and squash for extra carbs when I start amping up my mileage.
For training I'm a big fan of Galloway's walk/run programs and also Hal Higdon's training plans...both are available by googling them!
Best of luck!