Firstly, thanks for Mark offering opportunity to learn from educated like-minded !!

sorry that my first post is a bit overkill...

My story:
- I got into endurance sports running and skiing) 4 years ago, with none sport history.
- I have never had any weight problems (other than trying to get more of it..) this comes from my parents... so starting to run was not about weight, but probably 40-year crisis or something..
- I got coeliac disease 9 years ago, which led me to gluten free diet
--> I got fine and stay fine when I'm away from gluten
- after started to run I followed the "conventional wisdom" to eat lot's of carbs (and gluten free options are very high GI...)
--> I started to feel very tired afternoons/after meals and got my fasting blood sugar a bit too high
--> I then adjusted diet and replaced half of the carbs with wedgies and started to get better.

Now, I'm not Primal, but somewhere halfway between standard plate and PB. My lunches are mostly along PB, but on breakfast and dinner there are some carbs.
I do my trainings either before breakfast or dinner, which means I train quite fasted (I suppose)

The problem:
- I have ran 5 marathons (1*-09, 2*-10, 2*-11) and each time, after the run, I got odd symptoms (usually 1-2 days after). Worse the run more clear the symptoms.
- I seem to have some kind of energy problem on my marathons, in all runs I either cramp, or just loose steam around 25-29 km. But I have done several (15-20) training long runs with 25-33 km's and 2.5-3.5 hrs, some almost fasted and no additional energy on the run, without problems. They are obviously on lower hart rate (65%-70% of max HR vs ~82% on marathon)
- All my shorter distance "races" suggest much better perf. than what I can do on full distance
- In all Marathons so far, I have done "proper carb loading" (yes, despite I'm sliding closer to PB diet normally) and I have had sports drinks on the run and usually few energy gels.

- red skin (a bit like sunburn) on my neck/shoulders and under my chest, not itchy, not painful, but somehow a bit more sensitive than usually and when I press the red area it goes lighter and comes back red, a bit like sun burn.
- At the same time or after the skin reaction my stomach gets a bit loose & gas.
- All this goes away in few days.

I think this is quite a rear phenomenon. My general doctor don't have a glue and just says it is harmless.. I'm not so worried, but I think I need to react somehow.
I'm assuming that somehow my systems ability to process this high-carb-impact is poor (from birth or from my coeliac disease). So I'm kind of "carb-poisoned", insuling peaking state..etc (not measured, just assuming..)
So I'm looking a new marathon-nutrition-plan with less garbs in it

If someone knows what is going on I would be happy to learn more, but just getting in touch with "closer-to-PB-marathon-nutrition-plan" would be great !

Thanks and Regs "runningnout"