Wii Fit Studio is a stage in Super Smash Bros for Wii U, and unlike most new series characters's home stages, not on 3DS. Wii Fit Trainer is homeless on 3DS. How sad. But it's not as sad as R.O.B., who has never had a home stage at all ;_; lik dis if u cry evertim.
Wii Fit Studio is pretty amazing in the fact that they could come up with a Wii Fit Stage at all. It's a fitness room area with a treadmill, some Wii Balance Board platforms, and a massive mirror that shows the back of the room. The mirror is probably the reason that this stage didn't make it on 3DS, as it would be like if there were eight fighters on screen. The 8-Player version of this stage removes the mirror entirely. The mirror will sometimes disappear to show the Wii Fit Trainer doing some yoga poses. My favorite yoga pose is the corpse. I'm not very good at yoga.