I second Joe's sentiment . . . and thank you for such a thoughtful and detailed response. Now I have to spend a little time over a cup of coffee reading your post a few times to make sure I get it all. Your comments on recovery between intervals definitely gives me something to pay attention to in my spinning class tonight. (It's one degree below zero as I write this . . . Will it ever warm up enough to ride outside again??? ) -- Also, I guess I didn't realize that your body could actually adjust to levels of lactic acid, and more easily if you gradually increase those levels over an endurance ride. But what you say makes so much sense to me . . . Again, thanks, and I will keep you posted (and likely ask more questions) as I further digest your post. -- Also, must order the Sally Edwards book you are all recommending!