Ladies,
Back to the track today! We went easy, going 2, 3, 4, 5, and 6-mile distances. Danielle, Carrie, and Lauren went for the longest distance, and since Carrie hadn't been Garmined yet, she won the sweepstakes and was our data collector for today.
Carrie's run data here.
A word about Garmins in general... they are imperfect devices. The nature of a mobile GPS device, especially wrist-mounted varieties, dictates certain compromises. The accuracy of any GPS starts with the polling rate, or how often it looks to satellites to triangulate your current position. The more often the device polls, the more accurate the data. The trade-off is every poll eats battery. So... to extend battery life, the device polls less often. No biggie, right?
Sometimes yes, sometimes no. If your run is straight line, it doesn't matter a bit. When the GPS picks up your data, it's along a predictable path, so no real error is introduced. However, if you run a course with many turns, the polling rate can make a significant difference in reported distance. The Garmin can't draw curved lines... it only draws straight. That means if you turn a corner, and you hit the polling timing right (or wrong!), you could lose the entire corner on distance. The only thing worse than that would be to run on a circle.
Hillcrest Circle.
If you look at Carrie's data, you can see what the Garmin did to her path there. It's the best illustration of how accurate/inaccurate the technology is. The final piece to the accuracy of distance is the accuracy of the GPS itself. The satellite triangulation can pinpoint you to around 3 meters, fine if someone is trying to drop a smart bomb on your head, but it can lead to slight inaccuracies for an endurance athlete.
Here's the thing, and this was a long way to get there... always assume you went farther than your GPS tells you, unless you are doing a straight course. Every turn introduces error, to the tune of under-reporting the total distance.
Tomorrow we meet at the track again, Thursday will be the Hatchery. We are trying to build our running time ladies, so expect practices to start to take slightly longer.
Back to the track today! We went easy, going 2, 3, 4, 5, and 6-mile distances. Danielle, Carrie, and Lauren went for the longest distance, and since Carrie hadn't been Garmined yet, she won the sweepstakes and was our data collector for today.
Carrie's run data here.
A word about Garmins in general... they are imperfect devices. The nature of a mobile GPS device, especially wrist-mounted varieties, dictates certain compromises. The accuracy of any GPS starts with the polling rate, or how often it looks to satellites to triangulate your current position. The more often the device polls, the more accurate the data. The trade-off is every poll eats battery. So... to extend battery life, the device polls less often. No biggie, right?
Sometimes yes, sometimes no. If your run is straight line, it doesn't matter a bit. When the GPS picks up your data, it's along a predictable path, so no real error is introduced. However, if you run a course with many turns, the polling rate can make a significant difference in reported distance. The Garmin can't draw curved lines... it only draws straight. That means if you turn a corner, and you hit the polling timing right (or wrong!), you could lose the entire corner on distance. The only thing worse than that would be to run on a circle.
Hillcrest Circle.
If you look at Carrie's data, you can see what the Garmin did to her path there. It's the best illustration of how accurate/inaccurate the technology is. The final piece to the accuracy of distance is the accuracy of the GPS itself. The satellite triangulation can pinpoint you to around 3 meters, fine if someone is trying to drop a smart bomb on your head, but it can lead to slight inaccuracies for an endurance athlete.
Here's the thing, and this was a long way to get there... always assume you went farther than your GPS tells you, unless you are doing a straight course. Every turn introduces error, to the tune of under-reporting the total distance.
Tomorrow we meet at the track again, Thursday will be the Hatchery. We are trying to build our running time ladies, so expect practices to start to take slightly longer.
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