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From Fellrnr.com, Running tips
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* '''Form Power, Ground Contact Time, Vertical Oscillation, Leg Stiffness'''. These fields are all available via the Garmin [[Connect IQ]] data field, and can be viewed using Garman Connect.
[[File:StrydGarminConnect.png|center|thumb|500px|A view of the data collected using the Garmin [[Connect IQ]] data field with Stryd also connected as the Footpod, using a [[Garmin Fenix 3]].]]
=Stryd and Running Economy=
One advantage of Stryd is that it's power estimate can be used to then estimate [[Running Economy]] and [[Heart Rate Drift]]. You can read more about this at [[HrPwr]].
=Testing Distance and Pace=
I tested the distant accuracy of the Stryd using the same basic methodology as I do for my [[GPS Accuracy]] testing. (See [[GPS Testing Methodology]] for details.) I used a [[Polar M400]] configured to use the distance from the Stryd footpod. As you can see from the results, the Stryd is remarkably accurate, far better than any GPS device I've tested. My testing of pace is more anecdotal, but I've been able to hit my target paces using guidance from my Stryd. I've tested using a range of paces from 10:00 min/mile to 6:30 min/mile and the Stryd allows me to cover a given distance in just the right time.
=Stryd and Critical Power=
The Stryd app has started to support [[Critical Power]], a concept more widely used in cycling. The Stryd method of calculating Critical Power is to use one of 5Km/10Km race time, or a test protocol using just two durations. The research I've found on Critical Power suggests that more data points are needed to provide a valid measure of Critical Power, and especially W' (anaerobic work capacity). Most research uses a fixed power output to exhaustion rather than a time trial. A time trial includes aspects of pacing and skill, so this seems a poor substitute. (Typically, CP tests define "exhaustion" as when cycling cadence drops below 50 RMP.) I'd recommend using more test runs and using one of the many Critical Power calculators available online. Stryd also has an [https://blog.stryd.com/2019/07/09/introducing-auto-calculated-critical-power/ automatically calculated Critical Power], but I've not seen any independent validation.
=Stryd's Power Estimate Compared with Cycling Power=
I performed an incremental test with both Stryd for running and my Tacx Neo 2 for cycling. For running, I used a 400m track, increasing my pace from 10:00 min/mile to 5:30 min/mile over 14 laps. I then performed a similar test cycling, increasing the power gradually. I then mapped the power from each to my heart rate. In both cases I found a reasonable linear relationship between power and heart rate. Using the linear relationship, I found that Stryd power is generally quite a bit higher than Cycling power. For me, Stryd Power = (Cycling Power + 40) / 1.13, so 100w in Stryd is about 70w Cycling.
=Using Stryd With Your Watch=
Here's my notes on the compatibility testing I've done so far. I've had occasional issues with devices connecting to Stryd at the beginning of a run. I've not found any pattern to this, and it seems to impact both Bluetooth and Ant+ devices, so make sure you have a connection before starting your run. I've also occasionally forgotten to turn off auto-calibrate, which is another gotcha.
