I started spinning last fall because of a shoulder injury. I just started up again about a month ago after my shoulder healed enough after my surgery. It is definatly a way for me to do cardio indoors, which I hate. I am just wondering if anyone can tell me how I can learn about the intervals and the timing of bringing your heart rate up and down, and all the stuff they do. Is there a book out there that I could get?? I think spinning is going to help me when I can get back on my rel bike, but I also like the sprinting, and time interval stuff for training. Any clues on how I can learn this stuff?