When I first began teaching group fitness in 2010, I used to think I was begin kind by telling the participants to 'grab their equipment (whatever was needed) and a smile and ...blah blah blah.
Now, as I've grown leading fitness, I have shifted my message to "bring whatever emotion you what, whatever facial expression you have and I hope this class guides you further to whatever it is that you're looking for"
Since shifting my introduction, I'm encouraging folks to 'come as they are' and I prefer that way better.