How To Fix Stryd Dropouts

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GotoesUser
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How To Fix Stryd Dropouts

Post by GotoesUser »

I can't control when the Stryd starts and stops. It just starts recording when my foot starts moving and stops the same way. And I walk to where my run starts and then walk back so there's no way to line them up. I was hoping the timestamps would fix that but maybe somehow Stryd and my watch are actually 10s off? That would be so weird given that most things sync time fairly often, I'd imagine.

I wonder if what I want is different from "insert stopped time." My situation is that the Garmin stream will have a break--about 5 or 10s--with no activity. It's not that I am moving slowly, it's that I am not recording at all. But the Stryd stream will have data there. So I somehow want the Garmin stream to have values inserted there for whatever fields I am including. I guess just assuming they are constant across the breaks would work well enough. But none of this would fix that my actual workout is now misaligned with the structured workout I was supposed to be doing. So the Stryd app shows me missing power targets all over the place even though I hit them fine when I look via intervals.icu. But I actually don't see how to fix that. Your tool is merging the workout as I did it and it is now genuinely shifted from the one I was supposed to do. So I'd need a way to either trim out the spots where the Garmin is stopped or adjust the Stryd structured workout. Neither seems worth it.
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fulmar2
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Re: How To Fix Stryd Dropouts

Post by fulmar2 »

Sorry, I am having trouble understanding the start / stop thing. I figure that everything should align perfectly because both Garmin and Stryd have UTC timestamps, so they should “line up”. Sorry to make you do more work, but can you maybe send me a screenshot or explain to me like I’m 5.. I don’t have Stryd myself for testing…

Thanks for your help on this. A lot of my users come to me precisely because of Stryd’s issues.
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GotoesUser
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Re: How To Fix Stryd Dropouts

Post by GotoesUser »

First let me explain more clearly.

The pod starts recording with movement. In my case, a couple minutes before I start running.
After a short walk, I start my run.
Sometime during the run, the pod disconnects from the watch which causes a crash in the Stryd data-field for Garmin.
To fix that crash, I stop the activity and choose "resume later"
As soon as the watch is ready, I start a running activity
It offers me the option to resume the activity from before
I choose that and then "resume"
Now the pod and watch are connected again.
The previous thing might happen 1-3 times during a run (if it doesn't happen at all, I don't need to merge!)
I finish the run, stop the watch activity, and walk home.
The pod keeps recording until I (or at least my shoes!) stop moving.

So, I think, the Garmin FIT file will have small gaps, 5-10s, where I paused. The Stryd FIT file will not have those gaps. So what does your amazing merge tool do in that case?

The files I sent at the beginning of this conversation should be a good example of this!

It wouldn't matter much, except, the Stryd app takes the FIT file and merges it with a structured workout plan so you can analyze various metrics during different parts of the run. The current merge seems to create a file where the intervals don't line up correctly. My suspicion is that your tool produces a merged FIT file with no time gaps since one stream didn't have any. Is that correct?

Thinking this out it making it clearer to me! I think I want to be able to merge in a way in which if one stream has gaps, the other will be clipped during those gaps so the final stream has the gaps. Is that possible? Stryd might still get that wrong but if it does there is nothing I can do...
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GotoesUser
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Re: How To Fix Stryd Dropouts

Post by GotoesUser »

Okay. Thanks again for all the work on behalf of the Stryders out here...

Here is my attempt at single email with all the info (input and output files attached). Using your latest version (web-site as of 3/3/2026).
  • I choose the merge tool, select "Noon Run GIR (1).fit" and "Long Run+.fit"
  • I Choose the first "trim" option (shortening the longer stryd recording to the garmin recording time)
  • I uncheck "distance" from Garmin.
I have my watch set to take distance from the pod. So in the moments when they are disconnected I want the pod distance, not whatever the watch does. Though I have begun to suspect that the pod remains connected and just the connectIQ app has crashed.

On the stryd recording, under "advanced FIT fields" I check "all" for the subset beginning with "Form Power"

Output is FIT

I choose "Use Existing Embedded Distance" since Stryd claims to be more accurate than GPS. And I think the Gotoes calc is GPS based.

I choose "Use Distance" for Calculating Speed.

This results in "Merge_1.fit" which has the issue I am trying to fix. Notice where the intervals end up. If you look at the power trace, you'll see 5 1-minute intervals toward the end. The first began at 1:10:00 into the structured workout but shows up in this merged file at roughly 1:10:30.

That might not seem like a real issue but I am trying to put these back into Stryd and pair them to the structured workouts to see how well I hit my target power, etc. Obviously I can do all that in intervals.icu and often do but I'd like the Stryd side to work.

From the "Pace" data, I see 4 spots where it drops to 0 for about 10s. Those, I think, correspond to the moments when I had to "Stop->Resume Later->Resume" on the watch to restart the Stryd data field. So the watch is not recording for about 10s but the pod still is. 3 of them happen before the intervals. That means if the pod timing is honored, the intervals did happen 1:10:30 into the workoout. But I want the final merge to excise the bits on the Stryd recording where the watch was stopped.

So what I think I want is "remove short stopped time": moving forward through the 2 streams looking for places where one stream had gaps of over 3s and under 20s (these should be adjustable). At each of these gaps:
  • remove the matching data from the other stream
  • shift both streams remaining timestamps backward by the size of the gap
So you would end up with a workout that finished some number of seconds earlier in the resulting fit file than in the real world. But then it would line up with the structured workout timing, I think.

I'd want the upper limit so that real stopped time (traffic light, drink of water, collapse in exhaustion) gets recorded as it should. I just want to edit out the ones short enough that they are clearly this (annoying!) Stop->Resume Later->Resume thing.

Is that clear enough? I can expand on any of it if it's helpful. And I so appreciate all the work!
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fulmar2
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Re: How To Fix Stryd Dropouts

Post by fulmar2 »

Thanks for the detailed notes — I dug into your files and here’s what I think is happening and (hopefully) how to resolve it with the current GOTOES options.

Why this is happening
Your Stryd file contains four 10‑second STOP/START pauses (you can see them in the FIT “event” data). In FIT files, workout steps are driven by “timer time,” not absolute UTC time. That means any pause before your intervals pushes the workout steps later in real time. It also means that we cannot trim the Garmin Timeline (the one with the laps and “workout steps”). In your case, three 10‑second stops occur before the intervals, so the first 1:10:00 interval appears around 1:10:30 in the merged output. With the settings you selected, GOTOES is preserving those real stop windows exactly as they exist in the Stryd FIT. You can see where there is a start/stop by uploading any FIT file here: https://gotoes.org/tools/fit-file-viewer - the "start" event is event_type "0" and the "stop" event is event_type "4".

How to solve it in GOTOES
I am hoping that I'm correct in my assessment that the issue with Stryd displaying the time being offset is due to the fact that Stryd is using "moving time only" to align their display... If that is the case, we want to eliminate all non-moving time from your export from GOTOES. **Note: I'm not a Stryd user myself, so this is mostly an educated guess on my part. We want to solve two problems... first problem is to remove the stopped time, and second issue is that we need to make sure that we're actually including the workout/workout steps from the Garmin Device; without those you won't see the workout in Garmin Connect.

  1. How to remove stopped time (i.e. Ignore all stop/start events)
    This creates a single continuous timer from start to finish, which keeps interval timing aligned.

    - Output format: FIT
    - Try to Insert Stopped Time: Checked
    - Minimum Speed to consider moving: --DEFAULT-- (i.e. leave at 0)
    - Ignore Big Gaps: Unchecked
    This combination tells GOTOES to not use the stop events in the FIT and not generate new ones, so the timer runs continuously.
  2. How to Preserve workout steps:
    Make sure you include the workout / workout_step messages in the Advanced FIT Fields section by checking all of the associated checkboxes (under the "Advanced FIT Fileds" dropdown. If you don't do that, the structured workout definition will be dropped in the merged FIT. This is important if you're using structured workouts in Garmin Connect. Again, I'm not sure if/how Stryd deals with this.
As a test, I used the suggested settings and generated two test files. In both files, I selected only the Distance & Stryd specific Dev Data from the Stryd file. Then I took everything from the Garmin File (including ALL of the advanced FIT fields, which ensures we keep the workout steps)... and the only thing I eliminated from the Garmin file was the Distance.

I did what I outlined above (to remove mid-activity starts/stops)... and I created two files. In one file, I calc'd the distance, in the other file, I just used the embedded distance. Please note that distance calc on GOTOES should be really good.. because what I do is first calculate the inter-point distance.. but then I do a second pass and apply a scaling factor to ensure that all the inter-point distances add up to exactly the value specified in your "override total distance field". This means that GOTOES calc'd distance is usually superior to embedded. Of course, it requires that you don't have some majorly errant point... but if you do, you can always delete wacky points using the "Edit Points + View Map/Charts" button...

I think this will give you what you want; I looked at it in intervals.icu and garmin connect and the files look good now!
MedTechCD
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Re: How To Fix Stryd Dropouts

Post by MedTechCD »

GotoesUser wrote: Fri Mar 06, 2026 3:19 pm Stop->Resume Later->Resume thing.
There may be another more convenient solution depending on how the Stryd app works.
In stead of stopping the watch, can you switch profiles during an activity? If you can do that on the watch (not sure if you can but it is possible on a cycling head unit), create a profile with minimum data fields and make sure that no IQ fields are on that profile. Switch profiles briefly to reset the IQ field, go back to the normal profile. This avoids pausing/stopping the watch recording and thus no timing issues.

I am doing this kind of thing on an Edge head unit with the AlphaHRV IQ field. It sometimes crashes (but not that often) too, and when i see that, I switch to a very basic activity profile with just HR (which I named 'Reset Alpha') for a couple of seconds and then return to the normal cycling profile. The Garmin simply continuous recording during that profile switch and the IQ field is reset.

I have perfectly synced FIT data from my Coros watch and the Garmin head unit this way.

But this depends if a Garmin watch behaves the same way as the head unit. I'm not sure if you can change profiles without stopping on a Garmin watch...
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