Sorry for the confusion. This question was meant for CdCf.

He mentioned greater short term power and a decrease in endurance over the last year and just wondered if the two were related by way of distance riding technique. Often riders with increased short term power may actually use that power in the first quarter or third of a long ride. Later on this comes back to bite them.

Practicing longer rides like a good track racer could be the solution. You break the 60 mile ride into four 15 mile "laps" and try to start slow and increase power slowly throughout the ride. Each split should reflect greater power and possibly speed.