I want to share my workouts in a specific group, not to all my connections. This is not possible? Not logical at all? Why would you create a group if you have to share your workouts to all your connections?
Exactly as Andy wrote, Connections are supposed to be in a closer relation to you than group members. I recommend keeping only family and close trustworthy friends on the Connections list, and keeping all others just in a Group (or in multiple groups).