Eric's training has had other, unexpected effects.
Do you listen to music when you run? I used to. Fast salsa or French Caribbean music for speed sessions, loud, angry live Bob Dylan for the long runs. The fast stuff was great for setting a brisk rhythm, then loud stuff kept me going through the pain of a long hill, or the pain of the last 2 miles of a 13 mile run. It was a motivation and also a distraction - if I was listening to music then there was less of my brain reporting on the ache in my legs.
But that was heel striking. Bash! (onto the heel, braking energies racing up the leg). Grunt! (effect of deceleration). Oooff! (huge muscular effort from hamstrings to power forward with no momentum). No wonder I needed distracting. No wonder it hurt.
But now? Well, one of the things I love about the Eric style is the ease of changing gears. The engine just chugs away at the same revs, and you just adjust the gearing (stride length) according to speed or terrain. Now my long runs are not a battle and I really look forward to hills because I just change gear, stay in HRZ, and float to the top (hmmm, float isn't quite the right word, but you know what I mean).
So I don't need the music anymore and it's great. I'm more in tune with what's happening around me (e.g. early morning bird song), I can chat to my running partner, I'm much more aware of form.