Does it evaporate as you burn it? That can't be right, cuz then it would rain fat. So what does happen to it? Allow me to splain.
I'm just trying to determine what that funk is all about an hour or so into my long runs. I stay pretty well hydrated, so I don't think fluid loss is entirely it. It just seems like a governor is put on my system after about an hour of running. Could melted fat in my system have anything to do with it? Does it get in your bloodstream at all as you burn it for fuel? Sure we all have rough patches on long runs, but does anyone else predictably have them as I do?
And what about people who lose fat strictly through dieting? Where does their fat "go"? It isn't used as fuel. Yet, it still disappears. It's like magic.