Measure Any Course in Moments!

cwru track measurement
The right tools can help you measure any outdoor course, not just a track!

We all know it’s important to practice holding consistent pacing mile after mile so we don’t crash on race day.  But when you practice your marathon pace or your 10k pace or your lactic acid pace how do you know you are at the right pace? Maybe you rely on a GPS watch that jumps around wildly between paces. Maybe you drove down your street to estimate the distance with your car.  Or worse – maybe you gave up and just started doing workouts on a treadmill to be sure you don’t fall behind.  When you’re focused on fine-tuning all the details like I am, you want your lactic threshold workouts to actually stress and improve those systems so you get faster.

Several GPS watches, a foot pod, and four heart rate monitors later, I can tell you that nothing beats knowing exactly the length of your training loop and nailing the same time it every lap. After all, isn’t that why track workouts are done on a track? It’s certainly not because we like turning left.  On a track, we can check our pace every 400, 200 or even 100 meters, and luckily, with a little extra prep, we can do that for our off-the-track runs too.  And the best part is that it’s actually easier than finding clean-enough running tights on laundry day.Especially if you’re inclined to fine-tuning every technical aspect of training, you may have been frustrated knowing that you can’t accurately measure distance with a GPS watch. You know what that’s like:  you once measured out your street with a GPS watch and it was a mile. The next time it told you 0.98 miles, and once it gave you 0.96 miles.

That error could potentially snowball into screwing up your training. For instance, let’s say you’re training for a Boston qualifying 3:35 marathon time. If you’re off by 0.02 miles, your “race pace” run could be slow, prepping you to miss qualifying time by more than four minutes.

If you want to know the length of your training loop, measure it with accurate tools. You don’t have to calibrate a bicycle, get a fancy measuring wheel or even leave the house! Just use Use satellite image measuring tools on the Internet. These tools are very accurate and pretty simple.  Here are some instructions for a site I like, Free Map Tools.

  1. Type your location in the search bar and search, or you can click “Pan to my location” for the site to automatically find you.
  2. In the upper right corner of the map, set the map display to “satellite.”
  3. If it’s an option for the area, disable the 45-degree angle in the map/satellite menu.  The airplane imaging isn’t stitched together as well as the satellite imaging.
  4. Next, just drop markers to measure a course.

Let’s take a look at the loop I use to train for marathon pace, a loop on my parents’ street.

course measure 2
First we zoom into the course start area and turn off 45-degree angle if it is on. Drop the first pointer at a landmark that represents the starting point. I use the stop line at the end of the street.
course measure 3
If the course is straight, pan to the next turn and drop the next marker making sure you hug the most efficient path, just like how a real course is measured.
course measure 4
When you are done, make sure your last marker is at a landmark that represents the finish. If you’re measuring a loop like I am, drop the last marker on the start. I make sure I include the run across one lane of the street because in reality, I do that every lap.

This street lap from the stop line, around the circle, and back across one lane of traffic measures exactly 1420 meters. I get 11 chances during a 10 mile run to check my exact pace on the exact same course. Now that I know the exact length, when I go to the street to practice 3:00 marathon pace, I know I should be running  6:03 per lap.  If I’m off by a few seconds, I can fine tune my perception of pacing for the next lap.

When I was a kid, we use to say the street was a mile long. If that was true, I’d be an olympic trials qualifier running 6:03 laps! An accurate loop course is an important training tool. If you need help calculating the time for a lap at a particular pace, there’s a tool for that too. Plug in pace and distance and calculate lap time.

“But Jasmine, how do we know this measuring site is accurate!?” I’m glad you asked. It’s very accurate. Don’t just take my word for it. Let’s measure something we already know like Cleveland Hopkins Airport main runway 06L/24R and compare it to the FAA’s measurements. The tool is dead on at 2743 meters.

CLE measurement
Pretty cool, right?

What about for things that aren’t straight like my high school’s 400m track? Check out the image at the top of this post:  it measures 400m in the inside lane’s inside edge!

When you measure your course, here are some tips from someone who’s very attentive to accuracy:

  • Pick start and end reference points you’ll be able to identify again when you are actually on the ground like specific telephone poles or the particular edge of a driveway.
  • Just like a real race course, remember to hug the best line for the course when you measure
  • Use roads you’ve actually seen in person. Sometimes the landmarks you use as references look different from the ground.
  • When measuring using satellite imaging, roads and trails aren’t always visible under trees. If the path isn’t straight, you’ll need to use another method.

Where do you go to practice race pacing? Are there any other tools you use to make sure your pacing is accurate through your whole workout? 

I'm a subelite marathon runner, but I didn't come from a collegiate running background. Instead I'm trying to break into competitive running in my thirties. I write about chasing the dream of running with the elite girls and tell stories of adventures along the way. Watch me chase the next big thing.

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4 comments

  1. When I calculate my target race pace, I base it on the prediction that Garmin will measure my races long. When I run a half marathon, Garmin usually measure the course at 13.15 to 13.35 miles. So, if I have a goal of a certain time for the half marathon, I take that time and divide it by 13.35, not 13.109375 to get a better target pace.

    1. I guess I should be more clear about my comment above.

      My goal is to break 1:50 in the half marathon. One hour and fifty minutes is 6,600 seconds.

      So, to break 1:50, I need to finish in 6,599 seconds or less.

      If I divide 6,599 seconds by the official length of a half marathon, 13.109375 miles, I end up with 503.38 seconds per mile. This is 8 minutes and 23.38 seconds per mile.

      But if I divide 6,599 seconds by my estimated “Garmin distance” of 13.35 miles, I end up with 494.31 seconds per mile. This is 8 minutes and 14.31 seconds per mile.

      So, while I am racing my half marathon, if my Garmin display says that my average page is 8:13 or less, it is very likely that I am on pace to break 1:50 in the half marathon. If my average pace is between 8:14 and 8:23, it’s possible am on pace to break 1:50, but not certain.

      I think similar calculations can be made during training.

      But obviously, it is better to run on an accurately measured course, as you describe in your post. that way, you have a better idea how your training is progressing. If you rely on Garmin, you might be running your workouts a little too fast or a little too slow and you won’t know for sure.

  2. I know it comes across as a little nuts, but my pacing sucked less than 6 months ago and this made all the difference in the world– at least for me. I found using a loop for marathon pace miles was just as useful as using a track for intervals. Every lap should be exactly the same, which is something I defiantly can’t get from a GPS.