TomTom Cardio GPS Accuracy testing

Final GPS accuracy results for the TomTom Cardio published at http://fellrnr.com/wiki/GPS_Accuracy

DIY CoolSculpting: 2 Years On

Removing body fat with ice seems too good to be true. How well does it work, and how long does it last? Here's my update 2 year after my DIY CoolSculpting experiment. http://fellrnr.com/wiki/CoolSculpting

TomTom Cardio Review

How does the new TomTom Cardio running watch, with its optical measure of heart rate, compare with the best in running watches?

Audio for Tabata workouts

I've uploaded the audio I use for Tabata style HIIT workouts. The 20/10 second intervals are far too short to look at a watch, so audio cues work better. I also like having the countdown. 

Changes to the analysis of the GPS accuracy of running watches

I’ve made two changes to my code for analyzing the GPS accuracy of running watches.

1. My code was using the distance recorded for the first and last point in a lap, which should be the overall distance of the lap. However, for some watches the lap points do not reflect the complete lap, so I’m now using the distance recorded for the lap itself. 
2. I saw at least one file from the 620 where GPS data was missing for the first couple of miles, even though distance data was recorded. I’m now ignoring those situations as anomalies.

This has a number of impacts

• The accuracy of some devices improves slightly.
• The ranking changes slightly, with the Garmin 620 and 10 improving while the Fenix 2 drops below them.
• My testing of two different 620 watches now shows a greater difference between them. The original 620 now looks poor, but not terrible while the replacement 620 is far worse. This might explain why some people are seeing better GPS accuracy than others from the 620.

Comparing the accuracy of a Footpod with GPS

So how does the accuracy of a footpod compare with GPS? You might be surprised, but I've been using a Footpod whenever pace is critical, such as pacing a marathon.

Accuracy of GPS running watches updated

Lots of small changes to my GPS accuracy analysis. I've moved some of the details to subpages for clarity, used deviation from the true value as well as the mean, shown the average pace error, and more. Next up, a comparison with footpod accuracy, the Suunto Ambit2 R, Galaxy S3, plus looking at how GPS satellite position impacts accuracy.