Spinning Class

I had a great workout today on my Wii Fit and I am so sore! I hope I can keep it up every day.
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I got a flyer in the mail from a local gym. They offer a bunch of Spinning classes. My friend, who lives in St. George, has just started taking them and she says that they are amazing and so fun. She says that you just sweat like crazy during them.
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I think a Spinning class sounds fun, but I'm wondering if I will die during a class since I am so out of shape. Have any of you ever been to a Spinning class? Are they okay to take if you are like WAY out of shape? Do you have to keep up with all the skinnies? Would I totally humiliate myself???
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Just wondering - thanks!