It would be interesting to show some youtube videos on yoga /pilates/gymn and commenting on them!!
You could ask, for example:
-Who is talking in the video?
-Which are the advantages of pratising yoga/Pilates?
-What else can you see on video(objects, colours, non verbal attitude)?
A pictionary on the gym would also be very useful!!
Teach them action/movement verbs :stretch,lean forward, rise, repeat x times,get up,stand up, hold , bend, press, breathe properly, ....and prepositions/d irections:up, down, left , right...
Encouragement words are also essential:"well done!great!that �s it!fantastic!excellent!great move!"
You coul also make some role plays...with smooth music....
Hope this may help you a little bit!!