No Low Aerobic since 8.20 firmware update

Could you share an activity when you are running slow? It would be interesting to see the time in heart rate zones. You should probably spend most of the time in zone 1 and 2 to get low aerobic training load.

On my 945 with 8.20 I got lots of low aerobic since that is what I do most so it isn't a general issue with the 8.20 version. 

Of course

connect.garmin.com/.../7941476043

There was a 1KM tempo section in that run, but was mainly zone 2

It was labeled as Tempo which is Aerobic High: https://www.firstbeatanalytics.com/en/features/workout-labels/

Tempo is right next to Base which is Aerobic Low so you are close.

I think that it was a bit too short. Shorter activities will probably count as higher aerobic than longer ones.

The tempo section might also have messed it up.

Thanks for the reply e7andy, so basically, because I'm not running long enough, it's not counting the runs as low aerobic. I'll try a 60 minute plod either today or tomorrow and see what that logs as then

It could also be the tempo section that makes the whole thing to be tempo.

You might check heart rate zones, they can randomly change after a software update

Thanks for the feedback e7andy and roger_dennis. 

Looking over things last night, I've been in and changed the HR to use %max vs %lthr, and used the following page to set the zones based on age (38), and Max HR being 190 from a 6K road race completed a few weeks ago:

https://www.myprocoach.net/calculators/hr-zones/

I've had OHR turned off since yesterday, and only used HRM Pro today for HR data from the run:

https://connect.garmin.com/modern/activity/7954197049

Run was pretty slow and steady, and average HR was logged at 139bpm, and I managed to get some lower aerobic points logged

Definitely need an accurate max HR should be from a hard as hell portion hopefully a sprint at the end of a race (tunnel vision... dieing... ) lol   Race day, caffeine, not early morning, and heat all sure help w/higher HR easier as well.   Can always add a few BPM to max if you think you were fatigued or had a few more meters at that effort (HR would keep climbing a little).

The activity you posted was 150bpm avg and a good little section at >165bpm... probably skewed it a bit to higher aerobic benefit.  It ignores the zones from my understanding, mainly using your max HR.  But maybe how you had them set before. 

My low aerobic base training days or recovery runs I try to keep HR below 75% of max HR (often around 65-70%), I have my zones pretty close to standard basic %.  60-70% / 71-80% / etc.   Results usually seem right on point, todays 130bpm (67%) easy hour run... gave 2.8 aerobic effect "BASE" impact.    Max HR on run was 138 (w/195 max HR) - cold weather sure limits the high end for me, but the weight of gear&snow raises my avg HR at a given pace.   With 8.2 software, HRM strap, seems to work pretty well.

I don't think the OHR was part of it, it will stay on sometimes to prove you are wearing it for GarminPay (i believe...) also if your HRM strap drops out it will failsafe to optical.

What was the training effect for the training ?

I've noticed that keeping aerobic training effect during the training within range like 2.8-3.2 helps making sure the final score is low aerobic.