I took a bit of trial and error for me when I started running again as a diabetic. I always have at least a couple of High5 gels on me just incase and I do have a fair guestimate of what bg I need to be at before heading out for different distance runs, although when racing the numbers change slightly. I think I would be starting a run with a higher bg than others would though, but that is just what I have found to work for me.
I did have strange things happening when I first started though, and to a lesser extent after returning to running again after long layoffs due to busted knee ligaments or stress fractures. I found that initially the BG levels actually seemed to rise during a run, despite not having taken any glucose on the way round.
I'm about to start on a pump in the next couple of weeks though, so my years of practice figuring out how to deal with exerscise and running and what works for me all goes out the window and I have to figure it out all over again from scratch.
