We do it both ways. If you are doing heavy resistance, it's more of a rocking back and forth thing. If we're isolating certain muscles, we keep our upper body very still and hover over the saddle. That is difficult. Jumps still throw me but then again I'm not the most graceful of people.

It takes a while. If you have questions, ask your instructor. He/she might explain better what type of muscle group you're trying to work or what is trying to be accomplished by whatever move they're doing.

I remember my first spin class way back when. I had been doing a LOT of cycling at the time and even with that, I thought that spin class was the most difficult thing I had ever done. It just takes time to get used to it