High Aerobic Shortage - still no solution?

I have been tracking this myself for several months. It is true that if the ride is classified as base, you receive no credit for high aerobic, but it may increase Anaerobic a coupe of points if you spent any time in that zone.  The same is also true for rides classified Tempo, Threshold and VO2.  You receive credit for High Aerobic and Anaerobic, but receive no credit in low aerobic..  Ideally regardless of the overall ride classification you should receive something in each area if you spent any amount of time in those zones. This feature has been broken for quite a while and  I doubt it will be fixed.  

ac-cycling is right on this.

This issue is unfortunately not specific for E1040. I experience the same already for years on the E1030 and E1030plus. 

Even the qualification of a ride being Tempo or Basic is not very clear and consequent.

On subsequent Sundays I did more or less the same ride/route. Both a little more than 3 hours:

• Ride 1: 55% in Zone 2, 44% in Zone 3, IF = 0.70, hrTSS = 170 => Garmin: Tempo
• Ride 2: 56% in Zone 2, 42% in Zone 3, IF = 0.69, hrTSS = 183 => Garmin: Basic

Both had negligible time in both Zones 1 and 4.

The Intensity Factor IF (The higher the more intensity with max of 1.00) and the Heart Rate Training Stress Score hrTSS (= comparable with the Training Load in Garmin) are parameters from TrainingPeaks

The 0.01 difference in Intensity factor is statistically not really relevant and as you can see, Garmin still give them both a different classification which also gives a very different distribution over Low and High Aerobic Load. 

On the pages of other devices like E1030, E830, E530 you will find the same kind of complaints/messages.

Unfortunately this is poor quality Garmin Training analysis. That's why I started to use TP (but you need a paid subscription)

Has this been resolved at all? Or is it still an issue. Finding myself in the same boat.

830 user here

This is not an issue in reality. You have to understand how the Firstbeat system used by Garmin works, but it is not well documented in the manuals. 

In my experience, it depends on the average heart rate of the session rather than times in a certain zone, as well as the Aerobic and Anaerobic training effect scores achieved during the ride.

Check this link in the Firstbeat site

Firstbeat Analytics

I have been studying this system for a while and wrote an eBook about it. If it is not considered spam, I can post a link here or you can contact me in private for more information.

And has nothing to do with power.

Yeh I’m well aware it’s HR based but find it strange that time in zone doesn’t impact it and relies on overall HR for session.

Slightly annoyed as I did a tempo/threshold session today and saw no impact, but also had to deal with some HR monitor drop outs which wasn’t ideal.  

I am afraid it is unfortunately not even dependent on the average heart rate. It is only dependent on whether the Garmin HR qualifies a session as 'Basic' or as 'Tempo' or 'Threshold'. Only if it one of the latter two, High Aerobic value is added. 

As example: I did week on week exactly the same ride. Week 1 I followed the pre-programmed 4x20 min. blocks in Z3 with 10 min Z2 in between. Week 2 the winds were so strong that I decided to do all Z3 on the head and side wind parts instead of following the pre-programmed blocks. The amount of time in Z2 and Z3 as well as the average heart rate of both sessions turned out to be exactly the same. The deviation was less than 1%. Still the first session was rated as 'Tempo' and thereby mainly added to 'High Aerobic', the second session was quite to my surprise rated as 'Basic' and thus mainly added to 'Low Aerobic'.

Only by doing the heart rate distribution analysis in Training Peaks (is in the subscription part) I saw a bit more difference between the sessions. In session 1 I spent  more time in the lower half of Z2 and in the highest half of Z3 compared to session 2. This means that the standard deviation in the heart rate obviously plays a role. If you spend a lot of time in the lower half of Z3, then the session will still be rated as Basic and thus doesn't add anything whatsoever to High Aerobic.

This also goes for if there is relatively a very long time spent in Z2 where in the middle there were long (high) Z3/Z4 blocks. E.g. when you have to ride a longer time to get to the mountains to ride some (long) climbs. I did a 5 hour ride with in the middle 3 30min blocks of high Z2/Z3 (3 climbs almost equally long) with around 10 to 20 mins at Z2/Z1 (the descents) and still it was rated as 'Basic' so almost all added to Low Aerobic and a very small portion to Anaerobic despite not having reached those heart rates. Zero was added to High Aerobic

I have concluded the following for myself: I subscribed to Training Peaks because the Garmin Training analysis SW is way not good enough for proper training planning. Then I am not even talking about the enormous mess and faults if you want to look at the 6 Months and 1 Year training results in the web app.

..and indeed: it has nothing to do with power

Hi, I've been interested in learning about Garmin's algorithm for some time. I tried to send you a DM for the eBook, but I couldn't. Could you please post it here? Thank you.

As I mentioned, heart rate average is one of the factors, not the only one. There are others that should also be considered like Aerobic and Anaerobic Training Effects. All factors combined influence the results.

The link to the ebook is www.bicimapas.com.mx/.../

A remark about the training zones you have defined: 

I assume your anaerobic threshold heart rate is 170bpm.

if you use the anaerobic heart rate threshold to derive the other training zones from, then common training zone definition is:

Z4 = 95% - 100% of AnTh = 162 -170 bpm

Z3 = 85% - 95% = 145 - 161 bpm Aerobic

Z2 = 75% - 85% = 128 - 144 bpm Easy

Z1 = 65% - 75% - 111 - 127 bpm Warm Up (or recovery)

So this means that if you would do the same exercises with the above defined heart rate zones, it's a bit more likely that you sessions are from time to time qualified as Tempo or Threshold which does then add to High Aerobic instead of Low Aerobic only.

Exercises are only qualified as Tempo or Threshold by Garmin if there is sufficient difference in heart rate between the blocks done in Z2 and Z3/Z4 and those blocks should be rather clear to distinguish in the session especially if you do e.g. blocks of 10 mins Z3 with 10 mins Z2 in between as relative rest, otherwise there is a risk that the session is qualified as 'Basic' and labelled 'too intensive'.

Unfortunately you cannot change the heart rate zones of sessions done in the past.