(Mis-) Understanding the 800m

Image: onejourneytothenext.blogspot.com

I never know quite what to make of Fittish, a mostly running-related blog associated with the edgy sports website Deadspin. On the one hand, it’s exciting to see anyone writing humorous, irreverent, and oh-so-hip articles about our dear old dying sport. As an example, earlier this winter, a post about Shannon Rowbury began, “Dammit people, put down the fatty and pay attention to women’s middle distance track. U.S. women are killing it on a global scale.” On the other hand, Fittish tries so hard to keep the tone cool and/or ironic that the articles tend to devolve into gossipy riffs on fame, fashion, and lifestyle. After noting that she had just run the fifth-fastest indoor mile in history, the aforementioned post continued heaping praise on Rowbury for wearing lip gloss that matched the color of her racing spikes.

Last week Fittish ran a post by regular contributor Sarah Barker with the promising title “An Exercise Physiologist Explains Why 800 Meters Hurts Like The Devil.”

I enjoyed the article, which I thought did a pretty good job of capturing in words the singular agony — for beginners and Olympians alike — of this simple two-lap race. Alas, in spite of reaching out to well-known exercise physiologist Ross Tucker (“Science of Sport”) for insight, Barker mangles the physiology rather badly, producing a description of what is happening in the muscles that is approximately the opposite of what is really going on. Of course, one needn’t have an advanced degree in biochemistry to appreciate the physical challenge of the half mile, as we used to call it. Nevertheless, knowing what’s happening at the cellular level can only deepen that appreciation, right? So let’s take a closer look…

Barker’s article begins by painting a charming picture of innocence on the track, as untutored high school boys line up to run their first junior varsity 800m. In the author’s rendering, they haven’t warmed up properly, haven’t paid attention to minor details like how they should respond when the starter says “Set”, and so on.

Junior varsity boys have other things to do besides listen to their coach drone on about who is running what at the meet, and when to be there and something about a uniform. Gosh, whatever. This is track. You run as fast as you can. On a track. Duh. These junior varsity warriors have stepped to the line with no firm idea that 800 meters is twice around the track.

The starter’s pistol sets them in motion and they sprint like mad for the first 200m. Those watching might be concerned about whether these boys can keep up the pace, but the lads themselves are “untroubled by creeping doubt because, bless their skinny souls, this is the first 800 meter race they’ve ever run.” But we, who have seen many such races already know how this one will end. The second lap will dawn on them like the end of childhood, and their young legs will mutiny and refuse to work properly. By that point, no amount of earnest enthusiasm or external urging will prevent a monumental slow down. We know this will happen because more or less the same thing happens to everyone who runs an 800m, even David Rudisha.

Why does it happen so reliably? Here’s how the article tries to answer that question:

The lads’ muscles were firing at great intensity right from the get-go, using up oxygen like there was no tomorrow, or no second lap. Aerobic respiration was doing the trick for about 300 meters but greedy muscles demanded more energy than the available oxygen could process, so they turned to anaerobic respiration to burn fuel. Of course, the by-product of anaerobic respiration is lactic acid, a substance which, in excess, is toxic. Lactic acid changes the pH levels in muscles, causing cells to leak good stuff, like calcium and water that are necessary for contraction. Since the runners continue to ask their muscles to contract, the process compounds, creating a cellular environment that impairs muscles’ ability to contract as effectively, i.e. with as much force.

Where to begin?

When the boys sprinted from the starting line at an unsustainable pace, that action was made possible by the interaction of multiple energy systems within the working muscles. The first few seconds relied heavily on the alactic energy system, which is capable of making a lot of energy available to the muscles on short notice, but only for a few seconds. Because the continued fast pace required rapid and forceful muscle contractions for much longer than a few seconds, the runners’ bodies turned to a second energy system, let’s call it the anaerobic energy system, that is capable of rapidly converting stored glycogen to large amounts of usable energy. When fully deployed, this second energy system is also viable for only a short time, on the order of 30-40 seconds.

Both the alactic and anaerobic energy systems have the short-term advantage of being able to operate rapidly without requiring oxygen, and the long-term disadvantages of being relatively inefficient and unsustainable, generating metabolic by-products that lower the pH in the muscle cells and inhibit further muscular contraction. To provide energy over a longer period of time, the body relies on the aerobic energy system. The aerobic energy system relies on mitochondria in the muscle cells to process glycogen in the presence of oxygen. This process is far more efficient than either of the anaerobic processes, and is sustainable for as long as there is sufficient glycogen and oxygen.

It’s important to keep in mind that when running the 800m, all of these energy systems are used, with their relative contributions to total energy output changing during the race. It’s also important to note that most young runners have relatively undeveloped aerobic capacity, so there’s not as much aerobic “power” to contribute as there would be with a more mature, better-trained runner.

Returning to the first stages of the 800m race, it is quite wrong to say that for the first 300 meters, “aerobic respiration was doing the trick.” In fact, the runners were relying primarily on their anaerobic energy system, which was happily fueling the unwise early pace, while the muscle cells rapidly accumulated lactic acid. Now, in one sense I suppose it’s not completely wrong to say that lactic acid, or any acid, in large enough quantities is “toxic” in the sense that muscle cells won’t be happy at very low pH levels for long. But the body has mechanisms for re-processing lactic acid as another source of fuel. However, these mechanisms require oxygen, and when lactic acid accumulation outpaces the ready supply of oxygen and the time required for reprocessing, muscles will temporarily lose their ability to contract.

So what is really going on in the first lap is that yes, the muscles were firing at great intensity from the get-go, but no, they were not using up oxygen like there was no tomorrow. In fact, they — or rather their muscles — were doing a relatively poor job of using oxygen. Have you ever started an 800m and remembered after a few steps that you had forgotten to breathe? I have, and it’s not that uncommon. The initial energy demands don’t require oxygen, so there’s no immediate trigger to remind you to begin active and forceful respiration.

The thing is, like tuning a car so that internal combustion takes place with the right fuel-air mixture, pacing in the 800m is a matter of finding the right mix of anaerobic and aerobic energy systems to delay the inevitable muscle fatigue. In addition, both system must be trained to be highly efficient at that desired pace. An 800m runner must have a very well-developed anaerobic energy system capable of buffering the most catastrophic effects of high intensity running, as well as a well-developed aerobic capacity capable of contributing energy throughout the race, and especially in the final few hundred meters when the anaerobic energy system is bankrupt.

As a high school coach who regularly inflicts the 800m on young runners, I want to say a few other things.

In my experience, most new runners, even freshman boys, generally have a much better intuitive understanding of pace than the article gives them credit for. They know the race is two laps, and while they don’t know exactly what will happen on that second lap, they know that restraint is called for. Actually, the runners most likely to choose a suicidal pace are not the novices, but those who have a few races under their belts, but who haven’t yet explored what happens with a really aggressive first 400. In that category, I include runners who are thrown into the 4×800 relay and fall under the influence of the adrenaline, the peer pressure, and the general craziness and run their first lap in a 400m PR.

In defense of slotting new runners in the two-lap event, I’d also like to add that no one is ever lapped in an 800m. Even the slowest distance runner on the team finishes within a respectable interval after the winner. Unlike longer races, that’s not a bad experience to have as a new runner.

About Jon Waldron

Running and Racing have been important parts of my life for as long as I can remember. I ran Track and Cross Country at Amherst HS, back in the day, and am proud to have been training and competing with the Cambridge Sports Union (CSU) for the past thirty years. If my bones hold out, I hope to continue for another thirty. About a dozen years ago, I began coaching, first as an Asst. Coach at Newton North HS in Newton, MA, and for the past eight years, as Head Track and Cross Country Coach at Concord Academy in Concord, MA. I've been writing for as long as I've been running. I've been blogging about running since 2005, and after a two-year hiatus, began blogging at "the runner eclectic" in 2014. In my experience, writing about running is way harder than running itself. I also still have a day job, working full-time as a Technical Product Manager for Nuance Communications, based in Burlington, MA. Thank you for reading my blog, and please consider leaving a comment.
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2 Responses to (Mis-) Understanding the 800m

  1. ankit says:

    I came across that article too, and even with my cursory familiarity with physiology, had some cringeworthy moments reading it. I’m glad you gave it the treatment!

  2. Jon Waldron says:

    Thanks for the comment, Ankit!
    I can’t believe I spent so much time writing this post. I guess I just wanted to speak up for JV runners, and the 800s they manage to run quite well, all things considered.

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