It is odd this came up tonight, as my evening ride of 24 miles consisted of a lot of experimenting with cadence. I use a cadence counter. I started this last August and I must say my endurance and speed have gone up quickly since I started paying attention to cadence.
This evening I decided to play with the cadence during the ride. On my road bike I was in the little ring (50/34 compact) while the other guys were in their big ring. I hit a high of 132 during the ride, but mostly rode in the 110 range. Normally my favorite cadence is 92. This high cadence actually felt good, but I am not sure how long I could sustain.
It does not seem possible, but higher cadence saves your legs. I am sure there is a "point of diminishing return", but I do not know where it is.
As a reference, when I started using the cadence counter on a normal ride my cadence was 65 to 70. I have made a major change in my riding since installing the cadence counter last August.