Working on advanced running metrics (GCT, Vertical Oscillation, Vertical Ratio, Step Length) — help us cover more devices before we ship it

A few of you have asked for Ground Contact Time, Vertical Oscillation and Vertical Ratio as real activity streams instead of needing to set up a Custom Stream by hand. We’re building this now — support for Garmin (watch + HRM-Pro/Tri or Running Dynamics Pod) and Coros (with a POD 2) is implemented on our end, along with Step Length and GCT Balance/%, but it hasn’t shipped yet.

Where we need your help before we release this: we don’t have a confirmed sample from every device that reports this data, and want to make sure the field names line up rather than assume it works everywhere:

  • Suunto users (with a Stryd pod, or a recent Suunto with native running dynamics) — could you share a raw .fit from an activity with this data so we can check the field names line up before we release?
  • Amazfit / Zepp users — same ask. We know at least one Zepp file has this data; want to confirm it’s the same field names across firmware/models before this goes out.
  • Huawei users (GT Runner 2, GT 5, Watch Fit 4 and similar) — if you can get a FIT file out of the Huawei ecosystem, we’d like to take a look.
  • Polar users — Polar doesn’t export FIT natively, so this only applies if you’re pairing with a Stryd pod and pulling the file from Stryd’s own app.

Separately — several of you have asked about Stryd’s own extra metrics beyond GCT/VO: Leg Spring Stiffness, Form Power, Air Power, Impact Loading Rate. These live in Stryd’s own developer fields rather than the standard FIT profile, so they need a bit more care and aren’t part of this first pass. If you run with a Stryd pod, we’d love a sample activity (ideally the raw .fit, since Custom Stream exports can lose the original field name) so we can scope that as a follow-up.

If you’re willing to share a file just reply here and we’ll follow up.
No ETA yet — depends on getting these samples in.
Thanks!

@jimmy_james @Ruben_Fernandez_Gale @QuocNgo @ostero

For newer Coros watches with latest firmware update you get some of them without the POD, ‘from the wrist’ as Coros calls it.

  • vertical_oscillation (mm) is Vertical Oscillation
  • vertical_ratio (percent) is Vertical Ratio
  • stance_time (ms) is Ground Contact Time
  • step_length (mm) is Step Length

Balance is not being recorded from the wrist.

These names are almost surely identical to those from Coros + POD, but just wanted to share for completeness.

Hi @ryandev,

That´s great that you are implementing full Garmin Running Dynamics in intervals.icu ActivityStreamSet.

The Garmin Pod Running Dynamics Set that Stryd implements in Stryd Next an in Stryd v5.0 for Garmin watches is:

  • cadence (rpm)
  • fractional_cadence (rpm)
  • vertical_oscillation (mm)
  • vertical_ratio (percent)
  • stance_time (ms)
  • stance_time_balance (percent)
  • stance_time_ percent (percent)
  • step_length (mm)

Previous Stryd models (without RD pod support) use Developer Fields

Hope this helps