I have been asked a couple of times what I mean when I say spin classes. It's a group excercise class at the gym on a static bike. As the weather is now closing in & the days are getting shorter I shall soon be hanging my bikes up in the garage & looking to do these to keep my fitness up. On an average 1 hour class I burn somewhere in the region of 1000 calories & my heart works at about 90-95% of it's maximum. I usually leave a puddle of sweat round me when I've finished!!