Smiling Cat- I can't do anything in sports drinks with artificial sweeteners. Nuun uses sorbitol and it causes my stomach to cramp. I only do Gatorade, which the low cal does not have HFCS or artificial sweeteners. But my resolution (ot really because I am just doing this at the start of a month, any month would have worked) is to first give up artificial sweeteners and also cut back then eventually eliminate HFCS.
In the race the day before the migraine I had nothing but Gu and Gatorade. I think it was a combination of dehydration and then something else. I will keep focusing on tracking that. 
Incidentally I had a Mexican Coke last week (my first) which is not made with HFCS, it was amazing. Tasted much better, worth the calories.
Amanda
2011 Specialized Epic Comp 29er | Specialized Phenom | "Marie Laveau"
2007 Cannondale Synapse Carbon Road | Selle Italia Lady Gel Flow | "Miranda"
You don't have to be great to get started, but you do have to get started to be great. -Lee J. Colan