I don’t use Strava so my data flow is Stryd → Garmin → Athletica. I see traces of time in zones I wouldn’t expect, but for me it falls squarely under ‘noise’.
For example, in my Z2 run yesterday my Garmin data says my fastest pace was 8:30/mi. Athletica thinks I spent 3 seconds at faster than 6:00/mi and 24 seconds at faster than 8:00/mi. The Athletica data is believable - I could very well have run for a few seconds at these paces down some of the hills. And the discrepancy could very well be in how Garmin and Athletica present the data differently. It’s also less than 0.5% of the total time of my run. So I generally ignore it.
I’m not saying that you’re not seeing a real issue, just sharing what I’m seeing in case it helps figure out or explain what is going on somehow.
Then the issue likely stems from the data transfer between Apple Watch → Strava → Athletica. (Apple Watch and Strava show the same pace)
The discrepancies I’m seeing in time spent in pace zones can’t just be explained by data noise. Even on easy runs, Athletica shows several minutes spent in paces that I physically couldn’t sustain for that long. For example mondays easy run has 12 Minutes between 4:16 and 3:44 min/km. So something seems to be going wrong in the way pace data is processed or interpreted during the sync.
I think there are two different issues mixing up here:
1) running power is not showing up in Athletica
I didn’t have that issue. Was working for me for the last 6 months. Maybe has to do with me synching Garmin AND Strava.
2) Running with Stryd leads to wrong paces and time in zones
Power is correct for all of my runs. But there is always time in zones that I definitly did not touch. This happens on every single run with Stryd. Here’s the unsmoothed graph for my 30/30 session yesterday:
Looking into the fit file from Garmin, the fastest pace that was recorded is 3:43 min/km (4,488 m/s). So even the dip in zone 7 on the graph is not supported by the data.
Here zone 7 is starting at 2:29 and not 3:29. But that would make it even less likely that I would have spent so much time in this zone.
Perhaps the problem has to do with the fact that there are two pace sources in the Garmin file when using the Stryd? On the one hand, there is the pace calculated via the GPS track. And secondly, you can set the Stryd so that Garmin uses its pace and distance measurements - instead of those of the GPS. That’s how my devices is configured.
Does Athletica calculate the pace itself via the GPS or do you use the pace stored in the file?
1 - always been able to see my power data in Athletica since day 1 of the process. No issue there
2 - pace issue for me is just relative to the power. Easy runs are a little too fast and the faster runs are a little too slow. This doesn’t bother me though as I’m only really looking at power. The CP is very similar between Stryd and Athletica
3 - time in zone is off. My latest run yesterday says I spent 4 mins in zone 7 which I definitely did not do. Can’t figure this one out as my graph looks spot on. I spent about a minute overall in this zone across various points
4 - my pace zones vs planned is wrong as well. Zone 7 should be 6:22 and below, on the time in zone chart it says 5:13. Missing out a full minute between zone 6 and zone 7
Pace will depend on how it’s calculated. GPS positioning under good conditions will be +/- 5 metres. If you are running at 5 m/s (18 km/h) that means there is a high signal to noise ratio if working out pace from the second to second gps positions. If that’s what is happening you will get the odd spike in pace, that add up across an activity.
I noticed that @jhbuchholz posted the website determined WR alongside the watch WR. The WR IQ datafield uses the Garmin determined pace provided through the IQ API.
I’m still curious as to why WR would drop so quickly in the first few minutes according to the post-workout analysis. I would expect, and the watch WR supports, it in the 85% range.
My pace at this point has gone above Z2 for only a few seconds (on a downhill), and my HR is still in Z1 and well below my MAF HR. (note: this is not the same run as my pacing data above, this is a more recent run showing the WR drop still occurring)
But since the on the watch WR feels accurate this is more of a curiosity for me and I’m sharing my pacing data in case it helps the larger discussion and/or my WR curiosity.
Yes, pace zone chart is still off but power looks correct
Smoothed chart no longer shows spikes in faster zones I didn’t come close to running in, but time in zones chart still shows significant time spent in zones I didn’t run in.
Overview zones look close enough, so that’s not it.
Latest example…my run yesterday was a 40 minute easy run that I tried not to venture too much below 8:45 min/mile. Post-run my intervals.icu chart shows 1 minute and 19 seconds below 8:45, my Runalyze chart shows 2 minute or so below 8:45 (I think because this chart has it as 8:48), but Athletica shows a whopping 14 minutes and 15 seconds below a 8:45 pace, with paces going into the 6ish minute mile range (or a full 2 minutes per mile faster than the fastest pace I attained in this activity).
Not something that can feed to other IQ fields. But can understand why you might have that showing on your watch. I’d imagine Stryd uses a combination of accelerometers to detect footfall combined with GPS to calculate pace. The difference between all the pace algorithms will also be what level of filtering and / or smoothing is applied to the data.
Your WR dropping to 15% on the website is interesting. I don’t have insight into behind the scenes there. I wonder if the website is trying to use the Stryd power for the calculations, the datafield always uses (Garmin IQ API provided) pace for running.
