Walk in the Glow of Each Other's Majestic Presence

I think most Activity Partners are probably Sandbox Friends. I think the question would be, if you had to give up e.g. squash due to injury, would you try to find another activity in which to partner with them? On the other hand, I think a long enough association as Activity Partners can be a form of Lasting Friendship, but it depends a lot on the tone of the relationship.