I'm on the same page as Resi. I'm not just a indoor cycling instructor (14yrs) that is an outdoor cyclist as well, I'm also a personal trainer (9yrs) and I place the most emphasis on a safe ride that provides the workout they want, the training they can use and try to let them know the "whys" of each workout.

It's not aerobics on the bike, but it is using a bike for an aerobic workout. The best result of well run classes are clients that achieve their fitness goals...and if it also inspires them to ride outdoors...all the better!