The page 30 section on the different efficiency types is very interesting. Thanks for sharing.
They talk about three different types of efficiency for running:
Biomechanical efficiency - "the mechanical cost of running and includes such factors as energy storage and how wasteful a movement pattern is"
Neural efficiency - "an improvement in the communication between the nervous system and the muscles themselves"
Metabolic efficiency - "factors that impact the production of energy for the muscles to use"
Biomechanical efficiency at a certain pace will probably be improved by running at that pace and learning it.
Neural efficiency, if I remember correctly, can be greatly improved through strides, drills, sprints, and strength training - practicing using all the muscle fibers.
Metabolic efficiency should be improvable through any physical activity, including running and biking... right? I think that should be true.
In other words, I just stated what you have already. :D "Running at goal pace, sprinting, and strength training" should improve running economy.
"Frustrated runner," do you do strides often during or after your easy runs?
I also found this paragraph on page 33 (actual pg. 24) very interesting, it goes in the face of the "180 is the best cadence" movement: (RE = running efficiency/economy)
Again, very interesting article! Happy New Years Eve!