I read somewhere (maybe at 53x12.com, or maybe at slowtwitch, this CRS is killing me) that riding with a high cadence, using the slow twitch muscles, burns fat. Mashing the pedals at a slower cadence, burns glycogen. So you want most of your ride to be just as described by the OP, saving the glycogen for a sprint at the end. These guys at these sites support the OPs info also and I am like Will Rogers, all I know is what I read in the papers. My experience has been that riding a high cadence (90 - 100) on some nice rides with a few climbs (12% for a .5 to 1 mile) has helped me to lose about 15 pounds since the first of August. I know that is just anecdotal evidence, but it has been my anecdote. LOL.