So my sim took over Powerhouse shortly before Marcus Flex died in my game, and set some NICE workout clothes to be the club outfits for male and female adults.
Only to find that the next meeting all the elders in the club showed up in their skivvies! Poor sims. :-/ So yeah club outfits need to be available for all of the life stages that are available to join a club.
Like my T-shirt? Get it here: