This data is from a virtualpod, eh? Interesting.
Based on my quick look, power seems to increase as a quadratic with incline, while power increases linearly with speed. Stryd is mostly a linear increas with speed, too. And there appears to be a change around 7kph or 4.5mph…which I think it typically used at the boundary between running and walking.
Thanks again for posting the data! I’m planning to plot Minetti’s curves with your starting power values to see if the surfaces are similar.
The 3D plot. What did you use to plot them? It looks very nice (tho I don’t know how to interpret them. But nice!!)
The 7kmh is transition from Jogging to Running perhaps?
7kmh = 8:30km/min
That plot is from Excel. I’m mostly familiar with a spreadsheet, so I do a lot of work there or Libreoffice Calc. I’m bad with coding so I avoid Python, etc.
I’m a data analyst in my prev life. Pretty handy w the keyboard and excel shortcuts. Didn’t explore this bit of excel Plots tho.
Tx
Wow… I went to sleep and woke up to you doing quite a bit of work to get all this… 
Tx so much for your help.
I’ve not had much thinking time on this experiment. Thinking aloud (or in text) I’m asking myself
In My View, what would be the best way to do this experiment. (feedback welcomed)
It’s unfortunate that Stryd only supports 1BLE channel, otherwise would be great to run Stryd Treadmill App + RunCline / Garmin Watch side by side.
What I would like to do is to get the (flat) Power as reported by Stryd and the reported Incline compensated power. I think this can be achieved.
On Garmin Stryd Zones App, power (IQ) is reported, and I assume that this is “raw power (without incline compensation)”
on Stryd Mobile App, this output shows the “incline compensated power”
I think creating an equation to match this would meet the goal? (challenge is how to get the data to line up. I always use HR to try to match things up)
tx!
Tried downloading your file → got 404…
Here’s some more analysis from the Virtualpod data. See that the virtualpod increases for incline are less than 1% different than Minetti (Cr = running equation). Seems to be a good starting point for incline-adjusted power.
I did this manually yesterday night. I strapped on the stryd, then use the Garmin Stryd Zones datafield (to get power at 0%) and then fired up RunCline as well in parallel.
I then walked around for 30+s each time(i don’t have a treadmill), getting the relevant data at each incline (0%, 2%, 4%, 6%, 8%, 10% - I stopped between each incline change to revert the power back to zero. This was easier than figuring out where i changed the incline manually after the fact)
Then at the very end, I started jogging running (to get values <7.6kmh and > 7.6kmh)
After that, I combined the data from Garmin and RunCline and got the above data.
Note that when testing using the Garmin Stryd Workout App (which provides a way to input incline and inputing the same incline on Runcline, I found the values to be quite matching. This was not the same when using the virtualpod)
Oh, I think I get your data better now, thanks!
I had some time to look at your data and it provides some useful info, but I’m hoping someone can do a series of tests like what was performed with the virtualpod, on a treadmill with very controlled conditions over a wide series of speeds and inclines up to 20%.
Is there any reason the Stryd adjusted power from the app isn’t available? I’d like to remove Runcline data, since Runcline, I believe, is approximating Stryd’s data, like how we’re doing.
Based on the data, there’s have good agreement with Minetti until the 133 watt flat power value. Not sure what’s happening here…the predicted values are quite higher than the recorded values.
There’s 2 ways to get Stryd Incline Adjusted Power
For #1, The Stryd Mobile app doesn’t record HR, so it’ll be harder to match up the data to get Flat Power vs Incline Power
For #2, This works but is a bit cumbersome in that the grade adjustment via the watch is fiddly, but do-able. (esp now if I do those “complete stop”)
But for #2 to work, I would also need to have another Garmin that will record Stryd Power using Stryd Zones Data Field (flat power) and match up the data. (which I do, but don’t have a treadmill)
Best of both worlds would be if Stryd (FIT file) provides also the Flat Power + Incline Adjusted power. One can only wish…
I’ll have to find a treadmill and collect some data soon. Actually, I need a motorized elliptical oscillator that can simulate a footpath that I can use to set the speed and keep things constant. Maybe I’ll build one someday to test footpods.
It’s ideal to collect flat power on Garmin and incline power in the stryd app and then compare FIT files. Since I use Golden Cheetah, it makes comparing two FIT files really easy. They’re aligned by start time, so marking laps and getting averages can be simplified. No need to match by hr! Isn’t speed also something you could match by with Stryd app and Garmin? Just some thoughts.
Yes this works to some extent. Same for HR as well.
Stryd Does output the footpod speed. But I can’t remember if it’s there for both the Stryd Workout App and the Stryd Zones data field. (i think Stryd Zones Data Field doesn’t output speed - since it only reports flat power, so there’s no need to do any calculation hence not collecting/writing to the FIT file. Just checked - Speed is not there)
Based on my limited data set, this is the current outcome. (the line marked as final-eq2)
There’s a Deviation of -3% to +6% watt difference (which is about -7w to +14w)
I’m compiling this and gonna upload it for testFlight.
Would be great if there are people willing to test.
We may need to discuss on test procedures tho.
Note:FIT file will have data for
preferably you will need to have
Suggest that at each change in slope, you stop running. This will enable me to match the data (easier) after the fact.
Sorry for the late reply, but I’ll do a run this afternoon and send the files.
Here’s the plan…
Garmin Fenix 6 Pro
Polar H10
Stryd pod
Horizon 7.4 treadmill
I’ll do some running and walking at various speeds and inclines…
Will adjust incline on Treadmill and Stryd Mobile app-
Garmin IQ will show flat power, HR, speed, distance, cadence, etc
Stryd mobile app will show power with incline applied
I’ll provide both files (garmin / stryd)as well as the combined one
Tx!! That’s a great plan.
Are you using Stryd iOS app? If yes, means you’re on iOS.
This is the testflight (beta) of my app which I did the equation. If you have some additional time after your experiment, could you also just do a quick one with the BETA? (you will need to go to “settings → advanced options → Enable Stryd” and then use SLOPE mode, this will enable the +/- buttons to function as means to change the slope %)
Sorry, I’m an Android guy, latest version, 8.15.50, Apri 1, 2024. Let me do this run and then we can see what else is needed.
Just remembered…my kid has an iphone…maybe I can borrow that …
no worries. Just do this run first and I can use this data to match things up or see if the equation I have works.
only thing I see being the possible issue is to know when you changed the incline. (it’s not written into the FIT file) This is the reason I suggested to stop and restart at every incline change.
But I’ll still be happy to get any data.
i can use the lap function / standard time to keep track of the incline…
In the past, I’ve created a workout and uploaded it into my Garmin…the text would identify when to change incline…hmmm…
ok…finished the run, here’s what I did…
Created a workout in ICU.
–Varying inclines at same speed / various inclines at varying speed
–You can see the time stamp on when the incline has changed
Executed ICU workout on Garmin watch with IQ Stryd power zones field.
–Stryd pod was connected to mobile app and Garmin watch
–Any change in incline on the treadmill was done on the app. Figured I’d do both since you can use cadence, HR, etc if you want.
I have a few files to share but don’t know how…Help?
Stryd power center (Stryd app data / Garmin data)
Garmin connect original file
ICU workout file
