From 2004 to 2007, Jeremy Wariner was da bomb.

He was a skinny white kid running an event that — in the U.S. at least — had been dominated by African American men for years. In 2004, he won the Olympic Gold Medal in the 400m. He went on to win the World Championships twice, in 2005 and 2007, and won an Olympic Silver in 2008. His personal best of 43.45, run in the 2007 WC final in Osaka makes him the third fastest one-lapper in history, behind only Michael Johnson and Butch Reynolds.

During those years, he had very good speed, but never good enough to seriously consider the 200 (lifetime best of only 20.19). But for a certain type of track geek (including me), there was a time when we all longed to know whether Wariner’s slim build and smooth, efficient stride would enable him to move up and run a world-class 800m. I remember having an email exchange with track fan extraordinaire Josh Seeherman, who chided me gently for this fascination with Wariner and the 800m. As I recall, Josh wondered why the third-fastest 400m runner in history would WANT to dabble in a longer event and mess up his sprint training, and also cautioned me not to be taken in by appearances.

But in spite of the wise words from Josh, I still ached to know — what could Wariner run for two laps?

Now it seems that Wariner, about to turn 31, is playing with the idea of opening up the 2015 season with an 800. The report spawned a fevered LetsRun thread, and almost immediately launched a poll to predict how he would fare. The thread was introduced thusly:

“Everyone for years has speculated how fast Wariner (or any 400 guy) could run for 800. The boards have been populated with this talk for a LONG time. […] Some idiot even said he could run 1:41-1:42.”

I would point out that such speculation wasn’t there for any 400m runner, but was particularly rampant for Wariner, for the reasons cited above. He LOOKED like an 800m runner, and so in our thoughtless moments, we dreamed about him BEING an 800 runner.

Not surprisingly, the fingers of letsrun posterati have been tripping over their keyboards in their eagerness to predict his success or failure. The posts generally fall into two categories: those who feel that his 400m speed will carry him to a speedy (sub 1:50) clocking, and those with a more reality-based view of the matter. In my opinion, if he goes through with it, Wariner has very little chance of running what we would consider fast.

Why?

In any 400m, most of the energy for running is produced via anaerobic pathways. The best 400m runners have an almost miraculous ability to generate and use anaerobic metabolism to run at a barely sustainable pace while delaying the inevitable, desperate muscle distress brought on by ever-higher levels of hydrogen ions that are the by-products of anaerobic metabolism. “Strength” at the end of a 400m is primarily a matter of being able to buffer those by-products for as long as possible, while maintaining coordination of muscles that are in the process of failing.

The 800m is different (except for the coordination part).

In the 800m, “Strength” is the ability to find contributions from aerobic energy systems throughout the race, but especially at the end. Steve Magness, author of “the Science of Running,” points out that middle distance races do not become “more anerobic” at the end. Fatigue is rather the result of anerobic energy system failing, and aerobic energy systems being unable to produce energy fast enough to sustain speed. In both the 400 and 800, runners always slow down at the end. But in the 800, the slowdown take place more gradually and is offset to some extent, by a competent aerobic system.

So consider Wariner. Regardless of his build, he has been training for well over a decade exclusively (so far as we know) as a sprinter. Moreover, his high-end sprint speed has declined. He now runs 2-3 seconds slower for 400m than when he was in his prime. So he has less ability on the anaerobic side, and (as far as we know), no sustained work on his aerobic capacity. When he reaches that point in the 800 where aerobic reserves are needed, with what reserves will he respond?

I remember reading somewhere about the relative strength of 800m runners, expressed in terms of their 400m prowess. The author pointed out that someone like Seb Coe, was able to run an 800m at an average of 4-5s slower per lap than he could run 400. Someone like Alberto Juantorena, on the other hand, could only manage 6-7s slower per lap than his 400 time. Coe regularly incorporated aerobic capacity intervals into his training, and could run repeat 800s at an astonishing tempo, doing workout that required the kind of “strength” usually seen in 5000m runners.

Without extensive aerobic capacity work, I would be surprised if Wariner could average even 8-10s slower per lap for 800m compared with 400m. If he’s in 47 shape for 400, I wouldn’t be surprised if he struggled to run 1:54 for two laps.

Perhaps you’ll say I am fickle, for withdrawing support for an endeavor that I used to dream about. And perhaps I am, but I just think that the 800 has a particularly effective way of bringing the unprepared face to face with metabolic reality.