No Anaerobic training effect

Staying in th HR Zone 5 does not necessarily mean your muscles really work in anaerobic mode. Especially if the effort in Z5 is several minutes long, it cannot be anaerobic, since the organism cannot sustain anaerobia for more then a few tens of seconds. You need to do short bursts of high intensity, such as an interval training with max-effort sprints, or short steep climbs, heavy weight lifting, etc, to get an anaerobic effect.

Read more details on the topic here: What Is the Training Effect Feature on My Garmin Device? | Garmin Customer Support

The activity was a series of short anaerobic bursts 15secs - 1 min in duration totaling up over 50 mins to 10 mins. The activity was a wahoo workout. Surprised it records as anaerobic in the garmin activity breakdown but then zero for the training effect. 

Was it recorded by a Garmin device, or imported from Wahoo? You have to record it with a Garmin device in order to have the training effect calculated.

On a garmin fenix 6X. I’ve had it about 2 months so maybe it’s still learning me.

Hmm, after two months it should be already trained enough to process the data properly. If you dare, open the activity in Garmin Connect Web, make it public, and post the link to it here, perhaps we can find the reason.

Hi, Look at the following activity. Does it make sense that anaerobic training effect is stuck at 0.0? I really do not understand. I am on Fenix 6x v25.10   I am very confused.

https://connect.garmin.com/modern/activity/embed/10707652957

manudulux said:

Does it make sense that anaerobic training effect is stuck at 0.0?

Yes, in your case it does. I see no short bursts of maximal effort in that activity. Please read the article linked in my first reply here in this thread. There is a detailed description, with examples,  showing which kind of exercise will result in an anaerobic effect.

Thank you. Somehow I was expecting some value, ven if minor. But reading the article it makes sense indeed. Thanks for taking the time to look into it. Much appreciated.

So I contacted garmin support. Trux is correct. Anerobic effort during exercise doesn’t necessarily amount to an overall anerobic effort. 
to do so it needs heart rate and power to be increased and held for a measurable duration. From what I can tell this could be maybe closer to 2 minutes to register. 
i had the same issue and thought that I should have been registering some anaerobic effort.