I don't know if this is new or if I just didn't notice it before. I had the focus on a villager who apparently was just finishing the excersize routine and the message came up that the villager gained building skill. Since I wasn't quite sure what I saw, I watched another villager who was in the middle of the 'excersizing' behavior and at the end they gained building skill.

It's not a controllable behavior since they'll only start on their own and I'm not sure how much xp they actually get per routine. So I don't know how efficient it is over the long run compared to fixing up huts or polishing the temple.

Just thought I'd put this out there as I thought it was pretty neat.

Edit: I didn't really think it was that much of a spoiler, but thanks I guess.