When I'm out cycling I know that once I feel hungry, I only have around half an hour to refuel, otherwise I will bonk in a way that all performance is lost and it feels as if the only way to get me home is by pure will. This seems to be a rather common phenomenon since among German speaking riders there is even a name ("Hungerast") for this state. On the other hand I can go out for a 1-hour-plus run at similar intensity while already being hungry without bonking and even am able to push it hard at the one or other uphill during the run. Even if I push this quite far it does not feel as bad as in cycling but only gets more or less an "annoying" feeling that my thoughts start to revolve more around being hungry.
Does anyone have an explanation why this does feel so different in these two activities?