I was a spinner first, then the road bike came later. I have also been certified to teach spinning, but not in practice yet. I have asthma like the other gal in this thread, and can totally relate to the good and bad days. I have an old knee injury that bothers me on and off. One of the teachers does this bit of getting off and checking your spin bike computers, and changing resistence knobs. I modify due to the asthma and knee. She cranked my dial on a day when my knee was bothering me, and I had my eyes closed just enjoying the music. Didn't see her coming until it was too late. I swear, she made me limp for week with this stupidity. Lucky she moved onto someone else's bike, or I might have choked her. Completely contraindicated. I've told her this before, but she never seems to remember. Maybe I need to tape my asthma inhailer to my forehead. Teaching off the bike is suppose to have it's values they train you. But besides the knee story, I just personally do not like it. Yes, motivation is good. Students safety is very important if someone appears in distress. But, one of the fundatmental cores of spinning, is that "it's your ride". So, modification is completely appropriate.