Add Indoor Bike Miles

I do this by adding the mileage, watts etc. after my spin class. I log into Garmin Connect on my computer and edit the indoor cycle event there - adding all the stats.

But that doesn't update the watch, so my total miles is out.

Easiest way would be to add a wheel speed sensor to your bike (assuming you are using a wheel on trainer and not a direct drive) and pair it to your watch. The distance it records will never be the same as Zwift since it has no way of knowing about virtual climbs and descents but it will be close and you will then have data on the watch.

But that doesn't update the watch, so my total miles is out.

I agree, what we need is Garmin to enable the two way sync between the mobile app and the Connect web page when we edit the activity's mile information, just like everything else does.

I agree, what we need is Garmin to enable the two way sync between the mobile app and the Connect web page when we edit the activity's mile information, just like everything else does.

indeed. or at least allow updating directly on the watch

I came on here just to post something about this myself. I just came back from the gym and noticed no distance was calculated. I was wearing a foot pod sensor as well. The manual says a cadence sensor should calculate distance when used during an indoor bike session. The foot pod says it's a cadence sensor with "98% accuracy".

Why no distance with a Garmin Foot Pod during an indoor bike session?

I don't think that the "running" foot pod will be appropriate for tracking your indoor bike session. Maybe you can adjust it's settings in order to get some distance details, but i doubt it.

In general, I would like to see that garmin gives us the same possibilty as in indoor running. They introduced the possibilty to put in the distance from the treadmill manually. It should be the same with indoor biking, i.e. after the biking session when you press stop and save the activity, there should be a prompt to put in the distance. It's really not a big deal.

On a side note: Garmin should introduce a new method to calculate open water swimming distance as well. I mean, the Apple Watch can do it i.e. it calculates the distance without GPS. Considering Garmins trackrecord in sportwatches, I really wonder why they haven't come up with new ideas regarding open water swimming. Relying solely on GPS is garbage, given the fact that the Fenix 5 as well as Fenix 3 (and plenty of other GPS devices) struggle to find a strong signal next to a large lake or sea. Especially people who do breaststrokes barely see any distance in their open water swim, given the watch is located on their wrist and not on a buoy behind them.

Coming soon I guess...
http://newsroom.garmin.com/press-release/fitness/garmin-announces-api-integration-indoor-cycling-applications

While it's nice that they will have direct import from Zwift and other apps to Garmin Connect it's not the same thing that is being asked for in this thread. The problem is that at least for now data such as distance does not sync back to the watch and there is no way to directly input it on the watch.

I also miss the training recovery and effort based on Zwift-cycling.