Yasso 800s (Or, Just How Fast Can I Run This Thing Anyway?)

I tried the Yasso 800s this morning for the first time, just to see if my marathon goal is sound. (I had been running mile repeats as my track workout all season, rather than 800s.) I only did eight of them today, rather than the recommended ten, since I'd been set to do 4 mile repeats today, and I still have a couple of weeks left to fit in another attempt if I want.

Okay, here comes a bit of number crunching of no interest except other runners (maybe).

• My goal for the marathon is 4:35 (hours), based on the McMillan calculator and my actual past workouts.
• My goal for the Yasso 800s this morning was 4:30 (minutes), based on my previous results with mile repeats.
• My actual performance was 4:20, and I felt I could certainly have done another 2 repeats at that speed.

So I smoked them, right? I should be reconsidering my goal time, yes? That was certainly my first thought.

Then I started doing some more online research, mostly in an attempt to find an easier way to explain these to a non-running audience. I didn't find that (so I refer you to the original article about them in Runner's World), but I found a lot of dissent about the use of Yasso 800s, either as a predictor, or as a training tool. You can Google this yourself if you're interested.

I had thought a 4:20 marathon was too good to be true for me at this point, so I wasn't truly discouraged by what I read. Mostly what I take from my reading is that the Yasso 800s can be a decent predictor of performance (and not so much a training tool), and only if the necessary support is there (in the form of long runs, tempo runs, etc.). And that it's best to add on 5-15 minutes to that prediction time anyway. Which brings me right back to a goal time of 4:35. Maybe, possibly, cross-my-fingers, 4:25 if everything lines up beautifully that day.

I guess I'm spending so much time thinking about this because over the summer I've been frequently disheartened by my long runs. For a while it seemed like I just. could. not. do them at the paces I thought I should be able to. Everything else was lining up according to past experience and pace calculators, why weren't the long runs? (Leaving aside the issue of a hellish Chicago summer, of course.)

I had basically resigned my self to "just" finishing, as if that weren't accomplishment enough for my first time out. Although it will help with how I go about the marathon that day if I have a good and realistic sense of what I am capable of.

But finally, things seem to be a bit more on pace, ha-ha. The weather has cooled which makes a world of difference, and I feel like I'm getting a better handle on my pre-long-run nutrition needs as well, thanks to The Dude (still struggling with what to take in during my runs, alas).

I'm getting excited... I'm getting hopeful... what I don't want is to get crazy.

To any runners reading this, what has been your experience in predicting race times?