Well, the spring racing season is in full swing, eh?
Reading each weekend’s blog posts chock full of race recaps and PRs is one of the highlights of my week. However, I keep seeing one little thing that consistently bugs me.
Typically it goes something like this:
“It was a great race, but I was so mad because the course was apparently too long! My Garmin read 26.4 miles when I finished! What the feck!”
Umm…long course? That seems unlikely.
Race courses are generally measured as the shortest ground distance one could possibly travel from the start to the finish. For many reasons, the path that most people take is slightly longer:
Attempting to run as efficiently as possible relative to the shape of the course is often referred to as running the tangents. Note that depending on the nature of the course and its turns, this might require hugging a turn very tightly. Or it might require running in a straight line, as would be the case if your course were shaped like a python:
I want to run a Python-themed race, in which we all completely gorge ourselves afterward. Who’s with me?
So there are tangents. But why does that mean that my course couldn’t possibly have been too long?
Well, because the organizers probably put a lot of time and effort in to making sure it was exactly the right distance (along the tangents). If it’s a USATF-certified course, it will have been measured (and re-measured) using a highly accurate calibration bicycle according to the organization’s very specific and strict procedures.
I’m not saying that every race course in the universe is 100% accurate. I know I’ve run the occasional po-dunk 5K where the course was apparently designed by the town sheriff’s dog and the finish line was marked by a guy sitting on a cooler – and the distance was clearly not as advertised.
But for any semi-large or USATF-certified race? The course length is almost certainly accurate. In the case of major marathons and half marathons, it’s probably accurate. (Another sanity check: is the course is Boston qualifier? If so, it’s probably accurate.)
Ok, so say I ran circles around a bank of porta-potties in the middle of the race and logged some extra mileage. Why doesn’t that count?
It just doesn’t. Not when you’re running a race. Sorry. We all start in the same place and finish in the same place. Being efficient about it is part of the competition.
But what about my Garmin? Does it lie? How can I ever trust it again?
GPS watches are great training tools, but they are not perfect. Even if you somehow managed to run every centimeter of the course as efficiently as possible, your Garmin could still be “off.” A few things to consider:
(1) Garmins hate tall buildings. And tunnels, and underpasses, and clouds, and Ke$ha. (Ok, maybe the last one is just me projecting.) But really: all of those things can throw your Garmin off. Such is life.
(2) Garmins hate turns. I learned this one the hard way the first time I took my Garmin on a track workout. I’d known that the unit wasn’t totally accurate and might overestimate my distance a bit, but I was shocked at the magnitude of the discrepancy (and at the time even questioned the accuracy of the track’s length).
But no, the track was fine, of course. My Garmin just got its panties all in a bunch every time I’d go around a curve. (Which, on a track, is approximately 50% of the time.)
Since people who are much smarter than me have already explained the geometry behind this this much better than I ever could, I’ll just send you to this link if you’re curious about it. (Thanks, Kristin, for originally pointing that one out to me.)
(3) Garmins measure from high in the sky. The course is measured on the ground. And unless you’ve mastered the power of human flight (which would be, um, pretty rad), you are running on the ground. The GPS’s readings are an simply an estimation of your path on the ground from a point (or, rather, multiple points) in the sky. The ground measurement wins.
Okay, so how do I stop myself from running a gazillion extra miles when I race?
Here are a few things you can do to maximize your on-course efficiency:
(1) Run the tangents. Or at least try to. Duh. Although this can be tricky sometimes and isn’t always straightforward. For example, say the most direct path is to take a curve as close as possible – but often the inside of the turn is crowded, meaning you end up in a logjam if you try to take it tight. So you can either run a little more distance and maintain your pace or mash through the traffic and slow down. Depending on the circumstances, either one could be faster. It’s a crap-shoot! But hey, at least it gives you something to think about while you’re running!
(2) Run smaller races. Smaller crowds = less of the dodge and weave game. Plain and simple.
(3) Avoid races with lots of turns. It’s far easier to stick to the tangents on a course made up mostly of long straightaways as opposed to frequent turns. Although they’re still not perfect. At the Shamrock Half, I managed to pick up 0.06 miles (according to my Garmin) even though it was basically an out-and-back course, and I was at the front of the pack where the crowds were thin. In a 5K a few weeks ago, by comparison, I picked up almost 0.10 (obviously, over just three miles). There were a lot of turns in the 5K.
(4) Minimize side trips. Obviously you must balance your need for fluids with your desire for efficiency, but every time you dart across the road to hit a water stop (or say hi to your friends on the sideline, or poop, or barf, or do yoga, or whatever) you add distance.
(5) Plan for it. If you’re racing with your Garmin, build that extra distance in to your expectations. If the course has mile markers, you will probably notice how far “ahead” you’re getting throughout the course of the race, especially if it’s a longer race. Don’t let it take you by surprise and it won’t disappoint you.
(6) Ignore it. You’re out running your first marathon and you just want to have fun? Who cares if you tack on a few extra minutes! If it makes you happy, by all means, go high-five your friends. Efficiency isn’t always everything. Just don’t complain about the “extra” distance afterward.
Thanks for tuning in to my little Sunday PSA. I know this topic has probably been beaten to death elsewhere, but it seemed like reminder might be in order. If I’ve missed anything or you have any other thoughts/tips, please feel free to share!
And, of course, congrats to everyone who raced and/or PRd this weekend! (And slightly lesser accolades to those of us who sat around and drank beer!)