"There's only one hard and fast rule in running: sometimes you have to run one hard and fast."

Monday, December 17, 2007

Thought Experiment #1

Java's Crypt
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The Basis of All Running Training

Thought experiment one [bracketed sections are just for later reference]:

Imagine running for your life. For the first few steps, you accelerate and for a few more seconds (up to 15 seconds if you're a trained sprinter) you hold your top sprinting speed before your body tells you that you either have to stop or slow down. As you're running for your life, you slow just as little as possible. [phosphate system]

You run as hard as you can, breathing as deeply as possible, gulping air, as your lungs and muscles plead with you to stop. You hang on for 30 seconds to at most 3 minutes, when you have to stop or slow down. [lactate tolerance]

Something counter-intuitive happens: you find that if you shorten your strides, your stride frequency stays the same (it may feel like speeding up), your breaths aren't as deep and labored and you only slow a little. Though you keep gradually slowing, you can continue for 1-10 minutes, depending on your fitness. Once again, you feel you have to stop or slow down dramatically. [maximum oxygen uptake]

You find that, if you slow just a bit, your breathing changes from once every stride to once every other stride (a stride is two steps). This is more comfortable and you can manage this, though you slow continuously, for 10 minutes to as much as an hour before you feel compelled to slow again. If running over hills, one occasionally breathes every three steps for short periods.[anaerobic threshold]

Because you're still running for your life (what would chase you for an hour?), you slow down as little as possible and find that your breathing has changed again, to a very slow breathing rate, which is not constant - and you don't think about breathing at all - but you do think about walking. You run like this for as much as two hours when you need once again to slow down. [aerobic threshold]

At this point, you either stop, walk or shuffle. So you shuffle when you can, walk when it's convenient. The only reason you don't stop is because your life depends on continuing. After about a total of 5 or 6 hours of running, bad things start to happen. You wonder whether dying wouldn't be easier. Your legs don't work well and hurt all over. You are forced to walk. [glycogen depletion]

You can walk, if you have to, for many more hours.
The next thought experiment will help explain why this series is important and then I'll explore each of the different phases and why one can run races of more than 6 hours.


northwoods bryan said...

Without seeing an electrolyte source mentioned, wouldn't our freaked-out runner be slowed by cramps or some other hyponatremic failure mode before glycogen depletion?

As for resolving gylocen depletion, keeping running for longer than the six hours or so (even that is giving a lot of credit to mr. hypothetical) is going to require food intake on the run. Hopefully the pursuing predator chases the runner through an apple orchard or a 7-11 at one point.

In "Chasing the Antelope"/"Why We Run", Bernd Heinrich makes the point that human evolution to bipedalism was driven in part by selective adaptation to become the only predator that maintains such a long-term but mellow-paced pursuit of its prey - with the next closest long-lange-pursuit predators being packs of wolves. Jared Diamond cites meta-analysis that says the top causes of death observed in hunter-gatherer societies are inter-tribal violent conflict followed by intra-tribal violent conflict. My vote for the hypothetical predator is the strange tribe from the valley next door.

Birds of carrion might follow their prey for longer, but I doubt a raven or vulture would inspire such a mad panic.

Wayne said...

Interesting... I'm looking forward to reading the rest.

Colin said...

Hmmm, interesting. I may be wrong, but I'd suspect that the initial few minutes of the chase would vastly limit the length of time you could keep running at those slower paces.

There are, of course, different ways you could be "running for your life". For instance, suppose you were located a precise distance (5k/10k/marathon, 100 miles, etc.) from an underground bunker, and told that at some unspecified time (quite soon) a nuclear device will go off killing everybody outside the bunker. Your strategy as you run towards the bunker would be significantly different than what you outline, even though you'd still be "running for your life". Of course this would be more analogous to racing as we know it ...

Anonymous said...

Reading this reminds me of the 24 hour race I did last month. Of course no life depended on it. I thought of nothing except wanting to walk (more than just part of the uphills) for hours- putting it off until I knew I would be able to make my goal. I will be interested to see what you have to say about the different stages.
Karen G.