Precision Issue With Stryd When Walking and Its Solution

Mar 26, 2022

3 mins read

Recently, I discover an issue with Stryd which produce completely weak results when walking. The pace and the distance was completely wrong and makes the foot pod completely unusable. With the support, we could identify the issue and find a proper solution which work well before a real fix in the firmware. Here it is.

The issue itself

Configuration:

  • a standard Garmin walking activity, Power Tool is used as data field to view the power1
  • The Stryd foot pod is connected as accelerator to provide the speed and the distance. The ANT+ connection is used.
  • The GPS is deactivated2

I was then walking during 10 minutes and after first 2 minutes, I was running during 15s. The expected distance for this test would be approximately 850m.

Here is the result:

Pace Issue with ANT
Pace and Power issue with and Accelerator and Power Cycle ANT+ connection

lap Duration Distance Pace
1 2:42.2 0.18 15:00
2 0:15.8 0.02 12:03
3 7:21.8 0.06 00:00
Sum 10:20 0.26 39:41

We see that:

  1. the power when walking is always zero, except few seconds after running.
  2. there are some connection lost (glitches in the pace graph) which occurs regularly.
  3. the 3rd lap is completely wrong: walking 60m in 7 minutes is simply too few to be realistic. The distance should be near to 600m!

In fact, there is a conflict between the offline recording function and the recording controlled by the watch. The ANT+ connection starts the recording but, due to the fact that I did not run, the offline recording put the device in sleep mode after a timeout. This is of course a bug: if the user start to record a session, the device should provide the pace, cadence, distance and power as long as there is an active ANT+ connection.

The solution

Thanks to an answer to the Stryd’s support, we find two solutions to this problem.

The first one consists to add the Stryd Zone data field. This data field will avoid the shutdown of the pod during the session. It fix the issue but it is only a workaround because:

  1. This does not work with 3rd party ConnectIQ applications.
  2. It requires to consume one data field slot (of 2 max) for activities for which the running power makes no sense. (for example, a Nordic walking)
  3. For some activities, the user don’t want that it is analyzed by the Power Center because it influence the running metrics. (In my case, I don’t want that the trail activities are analyzed when I’m following a 10k training plan)

An other solution proposed was to used instead the Bluetooth connection. This is really good since that it has none of the disadvantage of the previous solution.

I had then a try and the pace, the power and the distance are now correct. Here the result on the same track:

Pace with BLE
Pace and Power with and Accelerator with a BLE connection and Power Cycle ANT+ connection

lap Duration Distance Pace
1 2:42.7 0.21 13:07
2 0:15.3 0.04 7:05
3 7:15.4 0.59 12:15
Sum 10:13 0.84 12:14

Conclusion

Simply disable the completely the ANT+ accelerator device on the Garmin watch and enable the corresponding BLE device. And with it, walking and running will be possible with a precise pace and distance measure.


  1. the effect on the pace and the distance is identical if no ConnectIQ data fields are used. ↩︎

  2. if the connection the GPS would then provide the speed and the distance. It would then not be clear which device is providing the data. ↩︎


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