A fitness center making use of fitness pack items including 2 rock climbing walls, pool with jump, nautilus machines, yoga studio, cafe with vending machine, massage table & chair, sauna, basketball hoops, boxing, changing & bathrooms, treadmills, hot tub, TVs, and dance floor & DJ booth for more fun cardio. Updated from original.

Gallery as a gym: https://www.ea.com/games/the-sims/the-sims-4/pc/gallery/CCE756F784F611EB8ED76EADD5D6A7E6
Gallery as a spa: https://www.ea.com/games/the-sims/the-sims-4/pc/gallery/21B21CB384FA11EB85996EADD5D6A7E6
Gallery as a pool: https://www.ea.com/games/the-sims/the-sims-4/pc/gallery/79F079DC84F511EB85C56EADD5D6A7E6