You can definitely eat more carbs than the average dieter. I was running 20-30 miles per week for a bit, but have recently cut back and am about to start training for another half. You should experiment. When I first did induction, I didn't run that week- I used the eliptical and chilled, took some rest days, etc. Now, I still don't eat many carbs...but on longer runs, I use shot blocks...I'm burning through them anyway, and at a certain point beyond 8 miles or so I start to hit a wall without something.