Your new group workout thing seems pretty cool but Is it possible to do group workouts with just friends?
I would like to do it with 2 or 3 real life friends rather than creating an event that everyone can join. Is that possible? if not I think it’s something you should add.
That would be really cool, although the implementation here seems definitely non-trivial (client side UI, server side ephemeral group support, seamless transition between standard workout and group workout).
I suspect we may see some third party training providers partnering up in the next few weeks and offering some organised winter training plans as group workouts…
I was hoping they would be able to add the ability to make events but let you set a password. That way you could use the current group workout feature but only have friends do it.
Given the current UI and typical smartphone screen real estate, having a bunch of private group events that 99.9% of all users would scroll past seems very clumsy… I guess you could redesign the group selection UI, but that would involve changes to ZML as well…
The design that first came to my mind would be an extension of the current “ride with” button. Friends are already near the top of the rider list, so that solves discoverability. All that would be required is some sort of UI preview of the workout and a yes/no “join workout” button. Perhaps also add a on-by-default “allow friends to join” toggle on the start workout screen, similar to “use ERG”.
Plus the server-side bits, of course. 
I’m not sure what to do about join-in-progress semantics though. Jumping right into VO2Max/sprints without any warmup is asking for cramps at best, and injury at worst.