My chain is on the big ring (farthest away from the bike) and about the middle of the rear rings (I often move to smaller rings in the rear when on flats or with tailwind). I think there are 9 rear rings if I remember correctly. If I shift to the little ring in front it makes a lot of awful noise so I tend to stay away from that... But I have a very hilly route and the wind is brutal out here, so maybe my problem lies there as well.

I have to agree with a lot of what Hi Ho Silver said - it's much easier for me to pedal slower and be in a higher gear because otherwise I am panting/out of breath. I don't get tired mashing around for 15 miles on my usual route. Today I only did 11 and at the end I was done. I think I am pretty much following all her posted rules about cadence already.

Maybe I am not doing anything wrong? Now I am confused. Sigh.

But, I would like to get faster, be more efficient and have better cardiovascular health, so that must be why higher cadences are more important. And then as you build better CV ability, you can spin just as fast in higher gears... right?