This hotel is probably one of the best places I have ever stayed. Both the hotel and the gym (Platinium fitness: https://www.planetfitness.co.za/platinum-sandton/) are absolute gems. Obviously the hotel guests get to go free to the gym. Gym has a full 25m swimming pool and two stories high actual gym, with everything you need and a bit more. Surprisingly even their own website doesn’t have any pictures of it..
I stayed there last time few years ago, so only borrowed pictures for you guys (sorry for that), but take my word, if you go to Joburg, stay here!