Thanks for the suggestions/questions, Oak. I'm not sure I understand why long intervals cause muscle damage. Maybe you could elaborate.

What seems to be happening with me is that my cadence is quickening to the point that I become overly breathless. Years ago (many years ago) I was a competitive runner in the 400, 800 and 1600 meters and cross country. It took me a long time to run comfortably at a slower pace, as I always seemed to revert back to my old training pace. Even now--though I'm far from being in good enough shape to run a sub-six mile--I struggle with keeping my cadence in check. Not that I'm running THAT fast now; just faster at times than I can handle.

I've never studied Chi Running, but for watching some Youtube videos just today. I'll be honest that I've never "studied" running. In my old running days, I just ran. There was nothing scientific about it; I was young and naïve. I also got injured A LOT, which is why I stopped running for a long time. Admittedly, I need to put more time and effort into figuring out how to train, on my form, etc., but I'll also be honest that I also want to keep it simple, too. I'm not sure I know enough to intelligently balance the desire to train effectively and injury free with the desire to avoid over-analyzing it, and I'm not sure where to start.

Okay, that's more than you probably wanted to know, and it's late so off to bed I go!