Hi, I just finished a Z2 33" workout on the bike as prescribed - the workout was loaded to my Garmin. However, after the workout, the data showed I hd only completed 22 minutes (it seemed to think I was not moving for 11 min). So, the AI coach has admonished me for only doing a partial workout, ha ha. What has happened here, and is there any way I can prevent it from happening again? Thanks!
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Sorry to hear this @Alyssa
Could you please share screenshots, from both garmin and athletica. It is always easier to understand the problem and report to our developer team accordingly when we have photos or screen recordings.
Thanks 
MJ
@Prof please note potential bug 
Looks like from the HR data you provided that your HR dropped several times to resting heart rate levels. Did you stop pedaling? Does your Garmin show similar heart rate graph?
Not sure but I think if you heart rate drops to resting levels Athletica thinks you are not moving (and rightly so).
If you didn’t stop and the graph doesn’t make sense to you, I would check your heart rate strap (I hope you are using one). Honestly when I look at your heart rate graph it looks pretty erratic. Optical wrist based sensors often look like this.
Anyway, please let me know if Garmin heart rate graph looks the same, which heart rate is this based on (chest strap or wrist) and whether or there are breaks in the workouts… one step closer to solving the mystery 
MJ
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Thanks so much, Marjaana! How weird - I never stopped pedaling and you can see the Garmin reported my HR as less erratic than what displays on Athletia…
But YES - I am just using the Garmin wrist-based sensor. I calibrated it with a Polar upper arm strap, but I understand that one may not be accurate either. I am willing to get a chest strap, but am a bit technology-challenged - I wasn’t sure if I could pair the strap with my phone and a) still be able to use my Shokz earphones while training or if these 2 things will interfere (I can’t seem to use the Polar arm strap and the Shokz at the same time) and b) if the HR data will automatically be uploaded to Athletica or if it will pick up the Garmin HR reading as part of the total workout data. If you (or any tech-savvy forum athletes!) could point me towards any resources explaining this, I would be most grateful!
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Your athletica hr reading is from Polar arm strap or Garmin wrist?
From Garmin wrist. Apologies for confusion!
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I use a Polar H10 chest strap. This has two bluetooth channels (you need to turn that on via the Polar app) and also broadcasts ANT+.
In the past I’ve paired it to my Apple TV (running Zwift) and to my phone (running TrainerRoad) simultaneously via Bluetooth while connecting my earbuds to the phone, also via bluetooth. So you should have no problems.
FWIW the HR picked up by my Garmin Vivoactive 5 watch is OK for normal activity but completely useless for indoor cycling workouts when it really doesn’t record anything like the HR values from the Polar strap. For all cycling workouts, indoor and outdoor, I only use the Polar H10 to collect HR data.
On the other hand, DC Rainmaker reckons the Polar optical arm bands are accurate even compared with the H10.
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Thank you @Robert for chiming in here.
@Alyssa - please confirm for me : both Garmin heart rate graph and athletica heart rate are coming from the same source?
Sorry I keep asking about the same thing, I just want to make sure I understand.
I noticed that you are looking at the chart on your phone…I find that the charts look more erratic on the phone, compared to a PC or even iPad…wondering if it looks different on a PC…I have attached the same workout - but the two charts - one from my phone, and the other from my PC…the phone squishes the info so it looks different…
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Aha! Thanks, @cmaloney - that could explain it! Will have to have a look.
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No problem, Marjaana! Yes, I am wearing my Garmin for the workout (no other HRmonitor) so all the data must be coming from that.
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Thank you, @Robert, much appreciated! I have read this doesn’t have a rechargeable battery. Do you need to replace often? And how do you see your HR in real time - does it display on your Garmin?
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The Polar H10 uses one CR2025 battery. How long it lasts depends on usage - I only use it when riding by bike indoors or outdoors, usually 2 to 3 hours a day. I haven’t tracked how long the battery lasts, but it must be several months. I unpop the sensor from the strap when I’m not using it.
AFAIK when you pair the H10 with a Garmin watch (uses bluetooth) and start an activity, it replaces the optical HR sensor of the watch so the watch displays the HR from the H10. I don’t use my Garmin watch for training though. The H10 pairs with my Garmin Edge 840 bike computer via ANT+ and shows up there. When riding Zwift, I pair it to the device that runs Zwift via Bluetooth, HR shows up on the screen.
I think accuracy of wrist optical HR sensors may depend in part on your wrist morphology - my wrists are skinny and bony! Supposedly the upper arm or forearm are better for optical sensors. But the H10 is picking up the electrical activity of the heart so it’s definitely the accurate way to go.
Having said all that, using a chest strap can be difficult for some people, especially women (at least, so I’m told!). But Garmin make an HR sensor that clips to a sports bra. I’ve no personal experience of that!
I’ll see if I can do a short spin on the trainer later today and compare the optical HR on a Garmin Vivoactive 5, the Polar Verity Sense arm band optical HR on a Garmin Vivoactive 3 and the Polar H10 chest sensor recorded via Zwift. Might be fun!
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A little field test! That would be great!
I’m a little baffled by this to be honest. Is your screen shot from mobile or desktop? (Should not make a difference as your Garmin shows pretty flat hr curve)
I did a first test comparing Polar H10 recorded via Zwift, Wrist optical recorded on a Garmin Vivoactive 5 and Polar Verity Sense (on forearm) recorded on a Garmin Vivoactive 3. There’s a timing issue between the Garmin Vivoactive 3 and the other two traces, and I need to do a more demanding test, but I’d say they track pretty well except for the opening minute.
Unless running presents particular difficulty for wrist-based optical sensors, which it might owing to arm movement, I don’t think I’d expect to see any unexpected drops in HR readings.
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