My take on cabhoydrate loading athletic sports is that the participants use exercise to give them permission to binge on carbs.
The theory behind carb-swilling-eating sports advocates that the more glycogen you have stored in muscle, the longer you can run or cycle. The simple theory is, of course, wrong because it does not incorporate the feed back loops and adaptations that occur in energy use and muscle enzymes when you change to a low carb diet. Second order effects are often ignored in most of the prevailing theories of physical performance and this is just another instance of that. I describe an experiment that shows that rats on a low carb (1%), high fat diet far outperformed those fed a standard diet (69% carbohdrate).
The next high performance fuel will be fat when the research finally gets it right. It is simple, our ancestors were capable of amazing performances and did it on fat, not carbohydrate. But then, could a performance supplement industry exist selling lard as the preferred performance fuel?