each place has different social dynamics. from my experience, working out at a gym isn't the exactly an easiest way to make friends. I've also frequented gyms in the past but there were moments that I needed to focus alone, otherwise couldn't get the gain I needed. the activity itself can become a social constraint in some cases.
when I've joined a social dance community, I was almost forced to talk and stand close with strangers. It is an emotional rollercoaster; it's all happy when I've met nice people but I've felt helpless when I had to dance/interact with people that I don't like, for whatever that is.
I've also practiced some type of acrobatics/solo dance for years and it is somewhere in between.
I think some type of intimacy heatmap can be made with all these activities.