Why would my training effect show 0.0 after a 1 hour Zwift ride?

Did you wear your Garmin device during the training? And if, then what is the model?

Vivioactive 4 and yes I wear it during exercise. But since I am on Zwift I don’t click on “Indoor bike” 

That’s the only thing I can think of. I would need to start a workout through the watch too. 

Allanna7304 said:

Vivioactive 4

I did not find in the specs of Vivoactive 4, nor in its user manual, that this model would support the Training Effect feature. It is also not listed on the page Understanding Training Effect on a Compatible Fitness Device. Are you sure you watch supports the feature? If so, could you post the referrence?

Anywway, have a look at the document Why is my Training Status not Updating on my Garmin Fitness Device? It tells the following:

NOTE: Activities uploaded via Zwift will not populate Training Status and Training Effect in Garmin Connect. This training information requires a compatible Garmin device.  

... and also:

• Indoor activity profiles do not generate a VO2 Max measurement.  Speed info from these profiles are prone to error. This would significantly affect the accuracy of Training Status.

  • One exception is indoor cycling. If you are cycling indoors with heart rate and power data the device will generate a VO2 Max estimate.

In other words, yes, you need to record the activity with your Garmin device, and additionally, at indoor rides, you need also a power meter connected to it

As per Trux, the VA4 doesn’t calculate training effect.