I noticed yesterday that most of my running is now stealth running with little noise except for the swish swish of my nylon pants and my hat brim scraping my nylon jacket.
I'm hoping that this means that my running is now a bit more efficient. I can use some extra energy at the end of my runs :) I think the reason for the change is that I may be developing better form as my body gets stronger. Because of my stiff joints, I've never had great running form (one runner told me I had my own style). Jeff Galloway, in his book Running Until You're 100 explained it this way. He was describing his "Cadence Drill" in which one attempts to take faster steps.
"In the process of improving turnover, the body's internal monitoring system coordinates a series of adaptations which make the feet, legs, nerve system and timing mechanism work together as an efficient team".