Spin class vs. riding

OK, so I went to my first spin class today.. RPM at Gold's.  I thought I was in pretty good shape.. just ran a marathon, did ok in a duathlon a couple weeks ago, and ride up and down the hills by me regularly on 15-30 mile rides once a week or so.

So how is it that a 45 minute spin class kicked the crap out of me?  Is it the same for you all too?  I mean I am really wiped, like post half marathon wiped.  Just wondering if spin class is that much different than riding regularly in terms of muscles used and intensity, or if maybe I am just a weenie, or both..

Just using different muscles and on someone else's pace besides your own.  Enjoy your new fitness challenge.  You'll be leading the class in no time.

Yo dude... You don't really use any dif muscles... the reason why you are wiped I am assuming, is because you are NOT doing interval work on the bike. I find that in Spin class, I am 60%-70% in Anaerobic zones and I like to use Spin Class as my interval work. Spin class is tough, but DOES NOT compare to riding a hill on chip-sealed pavement, with wind in your face, and 95  degree weather. It is another good tool to use and I usually do 2-3 spin classes a week on top of 125 + miles a week on my bike... Kudos for going to spin. Keep going, it will help you get faster on the road...

The spin class has been wonderful for my road riding.  The intervals and hill climbing in spin class has really been a positive for my hill clibing on the road.  In the past I would just sit down and take it, power climb the hill and hope I could keep the speed up so that I wouldn't have to walk.  Now I look at those hills as short interval attempts.  I'm still not as fast as the really good riders, but I don't give up on the hills any longer. 

With the bike and the run, I generally am not going all out breathless like I do in spin class.  Some of the hills will do this to me, but it's not by my intention, it's because the hill is a biotch.

In spin class it's only an hour, so you can go all out for that hour.  I don't think you would make that same intensity out on a 6 hour ride.  It's just a different kind of tired.

Try doing your 15-30 mile ride like it was a spin class, no resting, no breaks, no free spinning, go, go, go.  You will probably see/feel the same beat feeling.

 Spin is for me interval training, cardio.....but last week I took out my bike on the road.....boy what a difference, going up a "real" hill, hauling my body weight.....I think that it is different training, same muscles, in one you are doing interval training, at someone else's pace, the other...well your own pace, and your own body weight.....I'm upping my road/outdoor rides and keeping my spinning....it's fun...

i totally agree with the other guys, spinning is great for intervals (almost every spin class i've ever been to has been centered around some sort of interval workout).  And, it has definitely improved my outdoor riding.  it is a great complement but does not replace road riding like dan said.