Someone asked me how I manage "running by feel," and I simply said, "it's easy," and that's the beauty of running because running and everything related to it should simple, easy and fun. They asked what type of running I do and when/where/how and I said, I simply have a few combinations of running, based on "feel," which I think equate to 9 types of runs based on effort level and length of run which, by the way, is never pre-determined since I run by feel but I'll jot down what I did post-run.
Here's how I break down my running. I have 3 effort levels: easy effort, medium effort and hard effort, and don't ask me to define each level because it's inside and I know it "by feel," and by my stride, cadence, breathing and overall feel. I also have 3 type of runs in terms of length which I base on time (not distance): short (less than 40 min.), medium (40-60 min.) and long (60+ min.). The efforts levels and run types provide for 9 types of runs (for example, today I ran for 45 min. at medium effort so it was a medium (effort)/medium (length) run; yesterday was a 40 min. easy run so it was a short/easy run).
That's as much science and data that I need as a runner. Ninety percent (90%) of my running is some combination of the easy to medium efforts + short and medium length runs. The "hard" effort and "long" length runs only comprise about 10% of my running otherwise I'd get injured because if that became the majority of my running, I would over-stress the body (and mind).
So there it is for what it's worth. I don't follow complicated training programs and the like because I think they actually do more harm than good. The thing is, if you "run by feel" your body actually does establish a program that is customized for you. For example, if I look my log over the past 12 months, I pretty much do the following over a 12 day cycle of continuous running: 1 long run, 1 hard run, 2 medium run, and 8 easy runs (this is on average). Of course, I have no idea when/where I do my runs as my body & mind decides it on the fly but over a period of time, my running becomes pretty consistent. Then, of course, there's deviations where my body goes off and does things like 50% of my running hard for weeks or 100% easy running for weeks but these are uncommon deviations based on some physical or psychological factors that only my body and mind know and so they steer me a different way for a short period of time to satisfy some internal need and I have reason to question it because it's "based on feel," but over the long haul, definite patterns come to the surface.
Harry