Dee, here is a great description of spinning:

http://bicycling.about.com/od/trainingandfitness/gr/spinning.htm

It burns a TON of calories.....450 up to 900 calories per hour, depending on how fast you go, how much tension you use, and the techinique used. smile
_________________________
Inside me there is an angel whom I am constantly shocking...Dolly Parton