We have very high confidence that these changes increase accuracy for almost all users of the app. It included analyzing thousands of races tracked in the app, hand measuring routes in multiple cities, and running hundreds of tests. Recently, we made some changes to the way we filter GPS data in an effort to increase MapMyRun’s accuracy. Given its importance, we are always looking for ways to improve. We spend a lot of time talking to people about MapMyRun and accuracy is one topic that always comes up. Over a 26.2-mile race it could be over 10 minutes–the difference between qualifying for the Boston Marathon, or not.Īs a running app, we care deeply about accuracy. Overestimation errors that result from unfiltered GPS data can really add up. Official race distances are actually measured using a bicycle mounted tachometer (cyclometer), not GPS, which can often overestimate distance. Many runners learn the hard way that GPS-based apps and devices do not measure distance perfectly. But on race day, she finds she’s hitting each mile marker 15–25 seconds later than expected. She knows that in order to do this, she needs to run a sub-8:00 min/mile pace for the entire race, so she’s trained accordingly with an app or GPS device. A runner is training for a marathon, and her goal is to break 3:30. Here’s a story that happens all too often. By Jeff Knight, Michael Mazzoleni, and Conrad Stoll

Map my run google