So, You Made Us Suffer for Two Miles. What's Your Point? (Repost)

OK, this is another exceedingly long post about stuff.

I sort of fear being challenged on some of this - I'm no scientist, and I prefer to geek out on physics, but I can give you a poor, but usable, explanation of my poor understanding of what our bodies do, with some of the more hazily remembered numbers culled from the Internet, that bastion of infallibility.

So, when a boy or girl reaches a certain age...

Wait, that's the other thing I have a poor understanding of.

Running. Yes. So, our physical ability to run is governed by several things, of course, but the key fundamental component is our ability to burn fuel, which involves our use of oxygen at the cellular level.

Yeah, you have to physically get oxygen into your lungs and blood vessels and to the cells, and there are variables and potential roadblocks along the way. But all those extraordinary conditions as they may be, it still comes down to your ability to burn fuel.

Two of the key measures of this ability are our VO2 max, and our lactate threshold.

VO2 Max
Your VO2 max is specifically a measure of your body's maximal, or best, ability to transport and use oxygen. There's a couple of different expressions of it, but for athletes, we usually talk about milliliters of oxygen per kilogram of body weight per minute. It's generally accepted as the best measure of aerobic fitness.

Our VO2 max is largely genetically determined, but can obviously be affected by weight, and by training. The average VO2 max for untrained men is around 45 ml/kg/min, 38 for women. Decently trained athletes will get into the 50's and 60's, world-class athletes higher. Lance Armstrong? Reportedly around 86. Freak. A famous skier had an off-season measurement of 96. In the off-season, not at his training peak. Total freak. Interestingly, Wikipedia lists Iditarod sled dogs at upwards of 240 ml/kg/min.

Lactate, or Anaerobic, Threshold
So, VO2 max measures your ability to deal with aerobic training under maximum effort. At some point, though, your cells are burning at as high a rate as they can with the oxygen they're getting. Essentially, they burn through all the oxygen, and begin to rely on either creatine phosphate or glucose to burn for energy. This is anaerobic energy production.

There are certain byproducts of this new zone of energy production, including lactic acid. Up to a certain point, your body can reuptake it, limiting its build-up in your bloodstream. On top of everything else, Lance Armstrong has a freakish ability to reuptake lactic acid, meaning he can hold a higher level of intensity for longer than lowly humans, and recover faster. It's just not fair.

Once the demand for energy reaches a point and becomes even more inefficient, lactic acid production outpaces the body's ability to reabsorb it. Once it hits a certain level in the bloodstream, generally accepted to be, like 2 somethings per something else, you're considered to have hit your lactate threshold.

Very often, you hear people say they couldn't hold their speed or push more weight because of the lactic acid, which is technically wrong, or because they were lactating, which is completely wrong in almost every case.

Really, the lactic acid in the bloodstream is a symptom, not the cause.

Our higher-intensity workouts will push you just into the anaerobic/lactate threshold, which will help push it higher. And yes, this kind of training will benefit your distance running ability, as well.

OK. So, like... what?
I've done the testing. It's humbling, and not entirely comfortable. You run on a treadmill, with a huge mouthpiece jammed in your grille that, because of the noseplug, is your only way to inhale and exhale. You get pushed to successively higher levels of exertion for periods of time, and periodically, they jam a needle into your ear for a blood sample to test for lactic acid buildup. It is unpleasant, though you do feel like Steve Austin for a while.

From your VO2 max and lactate threshold, you can derive with some accuracy your predicted potential paces for other distances.

Running the two-mile time trial (remember, that's what all this crap was supposed to be explaining) bypasses all that testing, and essentially works this process backwards. Running it ideally, you are running at maximal capacity for a distance that is long enough to get you into the anaerobic zone, and long enough to not just be something you can totally will yourself through, yet short enough to run without spending too much time in the anaerobic zone.

You run it, and in an indirect way, it measures your VO2 max and lactate threshold. I suppose that doesn't matter, because just running the time through a formula, you can still determine your ideal paces. But I think it's good to know why it works.

Whew. Still with me? So, here's what you do. I'll email you your times. Take your two mile time trial time to the McMillan Pace Calculator. It's a magical thing that will tell you with freaky accuracy what your paces should theoretically be for other distances. You'll use these paces for some of our workouts, and you can use them as guides for your pace in races. Also, please note the suggested long run paces.

A final note about this: these paces are ideals based on your body's most fundamental capabilities. They don't take into account terrain, headwind, illness/hangover, a bad day, a good day, or the other things that start happening to your body when you hit a certain mileage. It has predicted my times well up to the half marathon, and then it breaks down for me. Honestly, I have yet to have my ideal, or even acceptable, marathon. I'll own up to that. But I've had some great coaches in the past, and I'm confident of my own coaching. It's just something I need to deal with and overcome.

So, don't live and die by these numbers. They're just a guide. If nothing else, the time trial teaches you to push your limits of discomfort, and for that alone, it's valuable. More on that later.