What Makes Fast Courses So Fast?

How fast is the Confluence Park course? You could ask Sierra Bower and Katelyn Maley that question. They know.

In the first segment of this article, I discussed my recent discovery that measuring courses by GPS or by wheel is at least mostly a matter of indifference. From there, I went on to discuss things that do make for meaningful differences between courses.

In today's Part II, I'll start out with how meteorological conditions can cause a course to vary from one running to the next. Then, we'll wrap up the article with a discussion of what makes Colorado's two fastest courses so fast.

Here we go, then, with meteorological conditions...

Wind - Like hills (discussed in Part I), the wind gives and the wind takes away. But the wind never gives as much as it takes away. The only true positive the wind ever gives you on a cross country course is that a slight wind can provide a nice bit of enhanced cooling as it speeds the evaporative cooling process of drying perspiration from your body. Otherwise, that wind at your back on one part of the course will inevitably be a wind in your face on some other part of the course. And it's always a net loss. It would get a little long to explain that here, but your physics teacher can explain.

Perceived heat - While you're running, the body is desperately trying to cool itself. Running is work. Work produces heat. Too much heat shuts the body down.

It helps to regulate body heat when the conditions are conducive to cooling. It hinders heat regulation if the conditions are not conducive to cooling. Over shorter distances, it doesn't matter much. Over 5000 meters, it matters.

Barring unpleasant wind conditions, temperatures in the 40s or low 50s are probably ideal for running a 5K. But, the perceived heat after sundown at 60 degrees may be less than perceived heat at 50 degrees in full sun. So, it's not just the temperature, it's the warming effect of the sun (or absence thereof) as well. Though we don't think much about humidity in Colorado, conditions of high humidity (particularly when combined with high heat) can enhance perceived heat because these conditions slow down the body's natural evaporative cooling process.

Oxygen density - I avoided using barometric pressure in the title for this section, but oxygen density is closely related to barometric pressure. The main difference is that oxygen density also takes into consideration temperature (which expands and contracts air masses as much or more than changing barometric pressure). When oxygen density is high, it is more difficult to push through the air, but there is also more oxygen to breathe. For distance runners, at least, the latter is more telling than the former. For sprinters, it's the other way around.

The evidence is overwhelming that more oxygen is better for distance runners in places like Colorado. The evidence is, as best as I can tell, mixed as to whether more oxygen confers any advantage in places like Los Angeles, which is very nearly at sea level.

If you're trolling for explanations as to why one course runs faster than another over multiple events at both courses, you are primarily asking questions about course conditions. If you're asking why a course ran faster at one meet than another, you're primarily asking questions about meteorological conditions--unless you have a special case, as when a course was muddy at one running and dry at another.

So, let's talk for a bit about Colorado's two fastest courses...

Liberty Bell is widely regarded as the fastest course in Colorado, though Confluence Park in Delta certainly makes a worthwhile claim for consideration as well.

I have better things in life to do than to travel to Littleton and Delta, pinpoint the start and finish lines of both courses, and then measure them (either with wheel or GPS, as it turns out). But, if we can assume that both are 5K courses, we can then invoke course conditions as a means of explaining why they run as fast as they do.

For Liberty Bell, the most relevant course conditions are that the course is approximately two-thirds asphalt and concrete (primarily the former, I believe), that the remaining third is very even, and densely packed, trail, and that it is both slightly and (mostly) evenly downhill. A runner can lock into a rhythm at Liberty Bell and stay there. Turns are few and mostly wide along the course.

Liberty Bell, of course, also benefits some from the carnival atmosphere of the meet. If you are amped up at the starting line, you've missed some serious cues along the way.

For Confluence Park, I'm not sure there is any asphalt or concrete aside from, maybe, a road crossing or two along the course, but I'm open to being corrected about that. If you visit Confluence Park, the flatness of the place is among the first things you would notice. It is a net neutral course, and the elevation profile provides no reason for a runner to ever have to change gears. You just lock in and go. Elevation is almost a thousand feet lower than at Liberty Bell, meaning there is more oxygen to breathe. Finally, races held at Confluence Park seem to be consistently held in the morning.

That last fact is important because it is cooler in the morning, meaning a denser air mass with more available oxygen to breathe. Generally speaking, any place on earth is cooler in the morning than the afternoon, but Confluence Park is a special case.

Allow me to explain.

At Confluence Park, the usual morning coolness is augmented by the fact that the property sits at the convergence of the Gunnison and Uncompahgre Rivers, meaning two different cold air drainage corridors meet at the park, dumping a massive pool of cool, mountain air at the venue daily. In morning hours, then, a very cool, dense air mass is the norm at Confluence Park.

It would be far more challenging to race in the afternoon at Confluence Park than in the morning. In addition to differences in oxygen density, the ambient temperature might easily be 40 to 50 degrees higher in the afternoon. Delta is one of Colorado's hottest cities--once the cool of the morning burns off. Paradoxically, at least until you understand the explanation, Confluence Park is one of the coolest places in western Colorado in the morning and one of the hottest in the afternoon.

Other courses fall somewhere on the spectrum of fast to slow, of course, but Liberty Bell and Confluence Park set the standards for the eastern and western halves of the state, respectively.

It's not difficult to understand, then, why runners flock to these two courses and why athletes urge their coaches to schedule meets at these venues. Racing is about running as fast as you can. Right?

Well... almost but not quite.

Racing is about running as fast as you can on a given course on a given day. Racing doesn't care how fast your PR on some magically-fast course is; it cares how fast you can run today's course. Each weekend offers a new course and a new today.

Given a choice between a team that consistently goes out and places well, no matter what course they run on, and a team with shiny Liberty Bell or Confluence Park PRs, I'll take the placing team every time. That team understands how cross country is won. Understanding is power.

A team that wins at Liberty Bell or Confluence Park might have an excellent understanding of how cross country is won, but, if so, they didn't attain it by looking at their PR times. I don't have to guess if the team that consistently places its runners well understands how cross country is won.

Ranking cross country by PRs is a little like ranking colleges by tuition. You trade off more meaningful measures of value for ones that are easier for the masses to understand.

In view of that, abandoning precise measurement of most cross country courses might be an idea worth some consideration. Instead, we could simply say, "Eh, somewhere around 5K." Think of how many things would be made simpler overnight with just that one adjustment. As faithful as that would be to the origins of cross country, however, we probably haven't yet engaged in enough turmoil over cross country PRs for that idea to be a likely candidate for adoption.

But maybe the thought process begins here.