One thing I noticed about runners after a run is that they begin to question the race distance. It’s probably because they are sporting a GPS-enabled device—maybe a watch or a smartphone. It’s also probably because they couldn’t believe their race times or the exhaustion they felt when they crossed the finish line. I know, for example, that the Ateneo-sponsored Run With ME 21K couldn’t possibly be 21K. I finished in PR time but I was far from exhausted and I didn’t go all-out in that event. What’s more, my Runkeeper app registered a distance of 19.95 kilometers. And it sure didn’t feel like 21K. As I saw the finish line looming in front of me, I asked myself: “Is that it?”
And as I walked back to my car, I wondered: how did they measure the race distance?
Let’s first talk about GPS devices. A lot of runners use their GPS-enabled Garmins or Soleus watches to keep track of their runs. Someone in some running forum will always post a comment claiming the distance as registered by their GPS device. Here’s the bad news: These devices are NOT 100% accurate. Readers may want to check this comparative study of 8 GPS devices. As expected, the devices performed poorly in trail runs, but performed relatively well when used in open areas with a clear view of the heavens. GPS devices rely on satellites that could be blocked or interfered by buildings, trees, mountains, even clouds. When I ran the Corregidor International Half-Marathon, my Runkeeper app, which is an iPhone app that utilizes GPS technology, was practically useless, not only because of the Malinta tunnel that cut through a mountain, but because the route hugged the hillside and snaked under heavy trees. What’s more, GPS devices takes the signal in intervals and then draws a straight line connecting the dots obtained in these intervals. It is not continuously communicating with the satellite. Think of those strobe lights you see in clubs, but at longer intervals. If the route has plenty of curves, the device will not register it as one smooth line. This explains why, in my experience, my device is off by about 5 percent if running around Bonifacio Global City with all twists, turns, and double-backs, but 1 to 2 percent off if running around SM Mall of Asia, which has long, straight stretches. You may think that a 5 percent difference isn’t much, but that means that the device would register a 21K run as 22k. So here you are, huffing and puffing, legs feeling like lead, thinking that you are just a few meters away from the finish line, only to find out that you have one more kilometer to go!
Which leads me to the next question: how can we tell if the distance claimed by the race organizers is in fact the correct distance? Did they just drive around the route and checked the car’s odometer?
I discovered how the International Association of Athletics Federation measures road race distances. And it involves a device that is called a Jones Counter. The Jones Counter is a device that is mounted onto the hub of a bicycle’s front wheel and counts the number of revolution of the front wheel. Even with this tool, measuring a road race route is not that straight-forward. Which side of the road should you measure? When switching from one side of the road to another, what route do you take? Should you “hug the curb” when you make a turn? According to the IAAF rules, you have to make a total of four calibration rides (two in each direction), and if the measurement on any ride is different on other rides, discard that ride and undertake an additional ride until four reasonably consistent rides are obtained. Complicated, right?
I don’t know if any of the race organizers bothered to measure the race distances in the manner described by the IAAF. If they did, then my hats off to them. But nonetheless, to truly remove any ounce of skepticism, here’s my request: make available the route’s GPX or KML coordinates for everyone’s perusal. These file formats allow the interchange of GPS data (waypoints, routes, and tracks) between applications and Web services on the Internet. This is how people load pre-mapped routes into their GPS devices. Runners can download the file and then load that file into Google Earth, Google Maps, or whatever mapping software that is out there to verify the distance. I don’t know why no race organizer has done this. I don’t think this is too difficult. It’s a one-time thing and it’ll give everyone a sense of comfort knowing that the runners truly get what they pay for.