Saturday, August 22, 2009

The Body as a Powertrain

Been pretty steady with training but not entirely satisfied: I keep on missing 1 workout a week, which has kept me in the high 20s for weekly mileage. Should be closer to mid 30s. So using that as an excuse, I turned today's Easy 4M into another experiment.

Near the beginning of the run, I started thinking about how I always have a pretty high HR on these runs. Wondered if that was just normal or a symptom of something. I know my max HR is higher than normal but that doesn't necessarily mean I have to be running at 180bpm all the time.

I broke it down into components: Air intake, Heart beats, Cadence, Leg power. To use a car analogy, the air intake (manifold, super/turbocharger) can control the specific power output of the engine, assuming a steady stream of gas (which in this case is available ATP). So the more I take in to my lungs, the greater amount of energy my heart can deliver to the rest of my body by enriching the oxygen in my blood a bit more. Cadence and leg power make up the transmission. Assuming equal power, pumping my legs higher/harder gives me greater "torque" while increasing cadence should give me greater speed.

In a modern car, there are electrical systems controlling all of these things and it can optimize the combination of these systems for different characteristics. For distance running, we want decent speed and efficiency, kind of like cruising at highway speeds. Analogously, I thought about how to get my bio-mechanical parts to function efficiently. Also, since I can't actually consciously control my heart rate, I assumed that the heart was sort of like a constant speed engine responding to need. Obviously it goes faster and slower but given a specific power output, the only variable I can alter is air intake to affect power.

So what I really wanted was a CVT. Keep my heart operating at an efficient pace and use transmission to effect acceleration and/or maintain speed. I noticed that I almost always have two-step in-out breathing cycles. Makes sense for higher work but filling and emptying my lungs that fast is wasteful for slow runs. So item 1: either breath more shallowly or slower. I chose to go for slower. Down to 4 steps for breathing in and 4 steps for breathing out.

The slower breathing should mean conservation of power, which should mean a decrease in heart rate. That would also mean a decrease in speed if I didn't change my transmission to a higher gear. So to compensate, I sped up the cadence and decreased power per step, the way decent distance runners do.

That was kind of a long walk for something people do naturally anyway but visceral results always work better for me when I have theoretical analogies in my head. Even applying it as I was thinking about it today made a pretty big difference though. I did a slow 8M about a week ago at 9:28 pace and 168bpm average. Today, the first 4 miles gave me a 9:39 pace and 148bpm. 148bpm! I never have heart rate that low. I then played around with breathing in/out on 3-step cycles, which gave me a 8:51 pace and 164bpm for mile 5. I then stopped thinking and just jogged and came out with a 9:44 pace and 159bpm. This last one was when I wasn't trying to speed up cadence and limit breathing so even though it's the last mile, I think the inefficiency shows. Big upside to this kind of running is that at the end of it, I was back down to 90bpm within a couple of minutes. It's just as fast but a lot easier on the body. Less waste.

Of course, changing my cadence dramatically means there are little bits of my joints and muscles that probably have to catch up. Also maybe my lungs. Goal is to have total freedom of all the controllable variables (air intake through lungs, cadence, and leg power) so that I can vary as needed. Kick down the transmission to power up a hill, kick it back up to cruise, and then pull out all the stops for the negative split.


Brandon Fuller said...

Running transforms you. I haven't put a lot of effort into breathing, form, cadence, or any of that. I just run. The result is that my body has changed -- not over night -- but season by season. I run with tiny steps now at my slow pace. Feels goofy if I think about it. But its massively efficient and I just naturally go there. I save those big strides and kicks for my fast stuff now -- which used to be the slow stuff. So no easy gains in this sport from what I have experience. Just run more.

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