Doing my best DC Rainmaker imitation, here’s a look at the data from a recent Zwift run using a couple of different devices for speed, cadence, and heart rate. The Zwift setup was done on a Windows 10 PC using a TreadTracker for speed, MilestonePod for cadence, and a Wahoo Tickr for heart rate. All of these were paired using the newly released beta for native Bluetooth devices on Windows 10. In other words, the Zwift Companion App was not used. The second device was a Garmin VivoActive 3 Music paired with a Stryd footpod for speed and cadence and using its built-in optical heart rate monitor.
The run was an 6 mile workout from Matt Fitzgerald’s “80/20 Half Marathon” training plan and included 5 miles of warm-up, recovery, and cool-down in Zone 1 with 4 quarter-mile intervals in Zone 4. The analyses was done using the DCR Analyzer.
The two heart-rate monitors tracked rather well after the first 5 minutes. I suspect the Wahoo Tickr (in blue) was not making good contact until it built up sufficient moisture while the VivoActive 3 Music was probably experiencing the typical “cadence lock” for the first minute or two. After that, they tracked nicely.
The pace returned by the TreadTracker (a device that sits beneath the treadmill and measures belt speed via contact with a spring-loaded wheel) and the Stryd footpod was almost perfect. The TreadTracker, being unaffected by a runner’s gait, is generally going to return a smoother plot and responds just a bit quicker to the treadmill’s speed changes.
As you can see above, the Stryd (in purple) is just a bit behind the TreadTracker (in blue) but settles in almost perfect. It’s worth noting that my Stryd has a calibration of 101.5 on the VivoActive 3 Music based on earlier testing with the TreadTracker. For this test, I probably should have reset the calibration factor to 100. Oh well…
Cadence is probably the easiest metric to measure whether at the foot or on the wrist so, not surprisingly, the MilestonePod and Stryd had practically identical results.