Originally Posted by
DaveLeeNC
riding long/easy improves your ability to utilize/metabolize fats in long/endurance events where riding hard will somewhat degrade this capability
I think there is some truth to that. But the trade off is that you teach your body to become good at storing fat to use later during long endurance rides. So if your only concern is increasing endurance it's a good thing. But if you are trying to loose weight and there is any chance that one day you will not ride enough miles to offset your recently enhanced ability to store fat, then you're screwed.