I would do 45 minutes of the two options. You need to allow enough time for an adequate warm up, instruction of the exercises and/or stations, actual time for the exercises, and cool down/stretch after.
You should have modifications ready for each exercise to accommodate all levels from beginner to advanced.
Hope this helps.
Hello Angie Lee,
I need an hour to properly warm up, cool down and instruct proper form with regressions/progressions. Maybe you could let the new students know that there will be catch your breath breaks and everyone works at their own level.
Congratulations and enjoy the classes.
Natalie aka NAPS 2 B Fit.