Originally Posted by
chasm54
I think you have this completely backwards. Training at high levels of intensity depletes your glycogen stores and they have to be replaced - this is what can trigger ravenous eating, and is one reason why racers need to be highly disciplined about what and when they eat. Long steady (NOT slow) distance rides burn fewer calories per hour but burn mostly fat rather than glycogen and are less likely to trigger uncontrolled eating.
I agree, this is part of the so called "Fat burning" zone (another thread). In general the higher the intensity the shorter the activity. You won't get much faster if you don't train hard, but if you train long enough at a moderate effort then you will be able to string out an activity(burn more calories) which otherwise would have depleted you far earlier. It is similar to the scenario between walking or running, you burn the same calories per kilometer but, with the walking your typical person can cover more distance which means more calories burnt(over a longer time period though).