How? This is much needed!

Have short video messaging. If bandwidth or storage is an issue: make them disappear like Snapchat/IG Story.
This will allow a lot more to be said, better connection with client and can demo small things as maybe a form correction or quick tip.

Would be nice if there was a way to send video just like you do progress photos

I would like to be able to send not just text messages but additionally videos to my trainer. I video myself in the gym for her to critique but then have to send it to her through personal text messaging. Please change this.

There is no option to share videos with the coach, only photos .
I think it is important to share videos of the excersise you struggle with to get the feedback how to improve techniques etc ....

I would like for my trainer to be able to add video of exercises if she wants to modify an exercise with either a regression or progression depending on where a client is at.

Enable video uploads so you can view and post your progress and also technique

Video recording of workout so that trainer can see and comment on the technique and rectify next time.