Wednesday, July 9, 2014

Garmin Fenix 2 - Buyer Beware

I've downgraded my review of Garmin's Fenix 2 to "buyer beware" due to the GPS accuracy problems. I've also updated my GPS testingresults with details of the 620 without EPO data and the Fenix 2 without WAAS enabled.

Monday, June 30, 2014

TomTom Cardio GPS Accuracy testing

Final GPS accuracy results for the TomTom Cardio published at

Monday, June 23, 2014

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.

Wednesday, June 18, 2014

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?

Friday, June 13, 2014

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. 

Saturday, May 31, 2014

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.

Wednesday, May 28, 2014

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.