What do you use as carbohydrates during long runs and marathons? I usually have gels or jelly beans but as they are highly processed foods, I would prefer a more natural source of carbohydrates.
I have experimented with portions honeycomb packed in cling film, but it was fiddly and sticky and therefore much too difficult. It is a pity, because I felt fine on it and I could obtain it locally.
Searching through the literature, I found an article describing an experiment whereby they used raisins instead of sport chews. Eleven male runners ran 80 minutes on a treadmill at 75% of their VO2max, followed by a 5 km time trial. They performed this workout tree times (on different days), once having water only, once having sports chews, and once having raisins. There was no difference in performance or gastro-intestinal comfort between the workouts with sport chews and the ones with raisins. Using water only, the runners performed less well.
The researchers also measured blood levels of glucose, insulin, free fatty acids and creatine kinase. The chews caused slightly higher insulin levels and more carbohydrate oxidation than the raisins, and creatine kinase was markedly higher in the raisin group. Elevated levels of creatine kinase are suggestive for muscle fibre disruption, and are used as a marker for delayed onset muscular soreness (doms), but the runners did not report more soreness when using raisins. The researchers could not explain this finding, which, I think, is a bit worrying.
I have not tried raisins out for myself, mainly because of the creatine kinase. Moreover, a marathon takes me so much longer than about 100 minutes of running, and therefore I am not sure that I will be fine.
Do you have any experience with this? Any advice?