stride deterioration

During my morning run I was thinking about how to approach this weekend's 20 mile race, and I recalled the moment in Again to Carthage when Denton says this to Cassidy: "I just don't think it's possible to practice for an event like the marathon. In fact, we don't practice when we train for the middle distances either. We do exactly what athletes do in almost every type of sport: we isolate certain functions and do overloading kind of work on each, one at a time. Then at some point we do a limited amount of integration work, blending everything back together."

In addition to the more obvious difficulties, one function (or disfunction) that marathoners need to prepare for is stride deterioration. In one sense we do this on every run because pure volume will help delay the onset of stride deterioration. But I'm interested in training not only to (1) delay stride deterioration for as long as possible, but to (2) maintain a decent pace when it happens.

It might be a big mistake but #2 is something I want to isolate during the race. My idea is to run at the slowest possible pace that will induce noticeable stride deterioration after eighteen miles. If I can do that, I'll have two more miles to practice the 'running with less-than-ideal mechanics' function.

The trick of course will be judging my fitness level accurately enough to select the appropriate pace. If I go out too fast and deteriorate early, it will create an unacceptable risk for injury. If I do the first eighteen too slow, my mechanics won't suffer enough during the final two.

Okay some specifics: I don't think a 6:30 pace will do it. Running eighteen miles at 6:30 is a serious workout but, assuming the race conditions aren't horrible, I don't think it's hard enough to cause much stride deterioration. At that pace I would have to go beyond twenty. On the other hand, doing 6:00 per mile is too fast. In my current condition and at that pace my stride would probably start to fall apart after twelve miles or so, and eight miles of bad mechanics is just too dangerous. Besides, it would result in an awful finish time -- reason enough not to do it.

I'll probably aim for 6:20 which would put me at 1:54 for eighteen. If I'm totally smoked at that point, well, fine. That's the point. I can focus on mechanics, coast in, and be happy in the fact that I've practiced stride deterioration. If it isn't quite hard enough and I have something left in the tank? That's fine too. I'd just try to finish hard and be satisfied with my first sub-2:07 twenty mile run.