The Heisenberg principle, recovery-run style
When I was racing well, or at least racing regularly and feeling confident about attaining a new performance level, my easy days were often very slow compared to others at my level. I embraced this, which was the proper response. As I was building toward my best period of running between ages 31 and 35, I did a lot of my 15 or more daily miles with the high-schoolers I was coaching, usually at no faster than 8:00 per mile and often considerably slower. To the extent I kept even a loose eye on the paces of these runs, I didn't have a GPS watch, so I was often making informed guesses anyway. I was usually doing a couple of pace-specific harder sessions every week; everything else was filler, and when you're nailing the workouts, you're basically pitter-pattering around for a couple of days -- albeit for up to two hours a day -- in anticipation of the next hard session. If you know that on Friday you'll be throwing back 15 vodka shots in the company of some outstanding prostitutes, you probably aren't particularly concerned about only getting to nurse Bud Lights while pleasuring yourself alone at home on Wednesday and Thursday. When the peaks are redeeming, you don't worry about the troughs in between.
Now that my return-to-racing experiment is over, my pace on any given run shouldn't matter to me one bit. There is nothing cumulative about my running other than the fact that if I only did it once a week or something, it would become harder and less enjoyable. In theory I could record every running step I take and never even look at it at the output, or I could just glance at the numbers from these efforts with the same level of concern as I do when noting in passing how much junk mail arrived this week.
The truth, though, is that because these easy-to-moderate runs through residential streets and on dirt trails with Rosie are now all I have to my quasi-sporting credit, I feel beholden to keeping the pace somewhat reasonable, even though I don't have even a loose idea of what "reasonable" means. This would be sad enough in any case, but given that I literally always run with a dog now, it's an abomination.
A guy I advise who's quite fast and very smart (he was born outside the U.S.) also runs at altitude, and he has a significant background in physics. I have a bachelor's in that field, which doesn't mean shit, especially since it was awarded before there were magnets or lights, but people who gravitate toward physical science tend to think in a particular way. This fellow told me as soon as we became involved that he refuses to wear a GPS watch on easy days. Instead, he just runs for time and guesses at the distance (and since he runs 90 to 100 miles a week pretty much all year, he's not going to get out of shape by overestimating by a mile or so a week even if this happens) or he just runs a loop of known distance and doesn't time it.
You've probably heard of the Heisenberg uncertainty principle, which has nothing to do with rogue high-school teachers cooking up meth and getting into fucked-up situations. In one phrasing, it means that the more accurately you can pinpoint the position of a very, very small particle in space, the less sure you can be of its momentum, and the more accurately you know its momentum (mass times velocity, more or less), the greater the error in your estimate of its position. That is, the error in your estimate of the momentum times the error of your estimate of the position has to be equal to or greater than a certain number, which is, again, very, very tiny. \
A more helpful way to see this is that the very act of observing or measuring certain things in this world has significant effects on those observations or measurements. This may be called the observer's paradox: If you don't assess something closely, you won't get any information about it, but if you do assess it, you change its properties. This is an issue with a lot of experiments in the social sciences that have human subjects.
Many of you, though probably not as fucked up as I am about it, can relate to this as it pertains to running: When I'm running alone (or with a canine partner), the very act of timing my runs from the outset affects my pace, even when I make every effort to avoid this. Almost always, I speed up, although sometimes it goes the other way. I know this because I'll turn on the watch for short segments and cover these at a pace that I know for certain I haven't been averaging to that point in the run. The difference might by 30 seconds a mile, it might be more, and it doesn't really matter for a host of reasons I've belabored here. But it happens.
Even apart from this, I enjoy my runs a lot more now when I don't record them. Despite having a compulsive nature in some settings, I've actually never been one to worry much about keeping careful track of distance on recovery days. Now that I am more of a hyperactive dog-walker than a runner, this is even more pronounced, and I like to stop and take photos or veer off across a field so that Rosie can home in on a squirrel (not off her leash; I don't think she'd hurt one if she did catch one, but lots of people have guessed the same about such shit and guessed wrong). If I head out the door and glance at my watch and am back inside in 62-63 minutes, I can be confident that I've run for about an hour because I almost always stop at an intersection here or to tie my shoes there or whatever. And more to the point, I'm not being audited by the Internal Running Service. If my goal is to run 30 to 60 minutes a day -- partly because I like it, partly because I have an obligation to the mutt, and partly to prove a point that hasn't clarified itself yet -- I highly doubt anyone's going to show up and demand that I prove that I've done so, government shutdown or otherwise.
The main message is that even knowing that recovery days can be startlingly slow while still conferring the desired benefit isn't enough to fully bunt ego and doubt out of the way. If you're looking to break 15:00 for 5K and find yourself bopping along at 8:30 pace the day after a hard session of 400s, you may wonder if something is up even though you're aware of the "recovery days are as easy as they need to be" dictum. But if you've just run the sub-15:00, you're probably fine, even indulgent, about your dawdling pace on the easy days. It's all ego and fear, rationally rooted and with perfectly understandable triggers. If you are obeying your body's mandates on your recovery runs and really don't want to know the numerical minutiae about them, then don't record these runs. If someone takes issue with this, get really drunk on vodka and start breaking beer bottles over their heads.