All right then that makes me feel better :-) Indy I don't feel bad at 186 but I can definitely tell it's hard. I also notice my HR on average is higher in spin classes which I think is because the rooms are so hot. I have gone up as far as 190 but not recently because it made me concerned. I guess what made me start thinking about this was a physiology lecture I attended earlier today and she said that your heart becomes less efficient at 180-200 BPM due to the fact that your heart has to have a certain amount of time between beats to fill with blood again. She also said that exercise over time drops your average HR but it was making me think then why now am I noticing such a high HR, of course I wasn't always an active person so who knows what a spin class might have done to me in my 20's??? Ok now I am rambling....